Mopping unit

Abstract: A mopping unit comprises a mop bucket (1) combined with a wringer having two squeeze rollers (2,3) mounted at the top of the bucket (1). An operating mechanism (4) for the squeeze rollers (2,3) includes a toggle linkage (12 or 13) comprising two toggle links (19,22 or 20,23) which are directly interconnected at a pivot P. When the two toggle links (19,22 or 20,23) are aligned, the toggle pivot P is substantially coplanar with the separate rotational axes (X,Y) of the two squeeze rollers (2,3) one of which is moved, to the operative wringing position, by the mechanism (4) on depression of a foot pedal (6).

Description: The invention relates to so-called "mopping units" as used with wet mopping systems, such a unit comprising a mop bucket combined with a wringer having two squeeze rollers between which a mop can be wrung out into the bucket. Mopping units are in general use for the wet and damp mopping of surfaces, particularly internal floor and wall surfaces of buildings such as offices and hospitals, and in the specification of our Application No. 86304235.4 (Publication No. 0207641) we have disclosed a foot-operated mopping unit requiring the use of only one foot with a squeeze pressure, applied to a mop whilst being wrung out, which is independent of foot pressure. According to that disclosure, the operating mechanism for the squeeze rollers mounted at the top of the bucket comprises a toggle operating linkage which, on depression of a foot pedal at a lower level, produces relative closing movement of the squeeze rollers. This operating linkage comprises two pivotally interconnected toggle links which go slightly overcentre to maintain the rollers at a predetermined spacing in the wringing position. The foregoing arrangement has enjoyed marked commercial success, and the present invention has for its object to build on that success by development of the toggle mechanism to provide operational and manufacturing advantages. US-A-1905556 discloses a hand-operated wringer device in which a movable roller may be moved selectively between two fixed rollers by means of toggle linkages connected to the ends of the movable roller. One link of each toggle linkage has an integral extension, and the extensions are connected by a transverse handle which is swung through an arc across the top of the mechanism to move the roller. According to the invention there is provided a mopping unit comprising a mop bucket combined with a wringer having two squeeze rollers mounted at the top of the bucket, and an operating mechanism for moving one squeeze roller towards and away from the other roller, which mechanism includes a toggle linkage connected to the movable roller and comprising two toggle links which are directly interconnected at a pivot which, when the two toggle links are aligned, is substantially coplanar with the separate rotational axes of the two rollers, and an operating lever which can be moved to bring the toggle links substantially into alignment and thereby bring the movable roller to an operative wringing position, characterised in that the operating lever comprises a foot-operated lever pivotally mounted on a lower part of the bucket and connected by a pivoted link to one of the toggle links, and in that depression of the foot-operated lever displaces the toggle links to a limit position, defined by a stop, where they are substantially aligned on opposite sides of said pivot so that they act as a direct strut to support the movable roller in the wringing position, the toggle linkage being slightly overcentre when in said limit position. This arrangement according to the invention enables the mechanism to create high wringing pressures at the rollers, whilst the toggle links can maintain the maximum roller pressure without any flexing in the mechanism as a whole. The arrangement whereby the toggle linkage goes very slightly overcentre to a limit position defined by a suitable stop will accommodate manufacturing tolerances and general wear in the mechanism. It also enables the linkage to be self-maintaining in the wringing position independently of applied foot pressure so long as the wringing reaction pressure is applied to the movable roller. Preferably the toggle operating mechanism is duplicated at the two sides of the bucket, whereby balanced operating forces are applied to the two ends of the movable roller. Preferably also one toggle link of each toggle linkage is directly and pivotally connected to the corresponding end of the movable roller, and pivot mountings for the movable roller attached to the connected toggle links are slidably guided in guide slots along the top edge region of the bucket. The other roller, which will in most cases be the front roller, is preferably adjustable so that the predetermined spacing of the rollers when in the wringing position, determined by the toggle linkage, can be varied to adjust the actual squeeze pressure applied to a mop of given thickness. For example, with a given mop the pressure may be adjustable to wring out the mop according to whether it is to be used for wet or for damp mopping. In a preferred embodiment of the invention, therefore, said other adjustable roller may be rotatably supported between two pivotal adjustment levers respectively pivotally supported on the sides of the bucket, below the adjustable roller axis, and projecting at the top of the bucket for manual adjustment of the angular position of the levers. The axis of the adjustable roller may be adjustable over a shallow arc generally aligned with said guide slots in side view. There may be provided detent means to retain each adjustment lever in adjusted angular position, comprising inter-engageable formations on that lever and the corresponding side of the bucket, the adjustment levers being mounted within the bucket and being rockable inwardly, against springs disposed between the ends of the adjustable roller and the levers, on the lever pivot mountings sufficiently to free the detent formations and allow angular adjustment of the levers. The invention will now be further described with reference to the accompanying drawings which illustrate, by way of example, a preferred embodiment of mopping unit. In the drawings: Fig. 1 is a schematic perspective view, drawn to illustrate the novel operating mechanism of the invention; Fig. 2 is a side view illustrating the kinematics of the mechanism; Fig. 3 is a side view of the preferred construction, with an outer wall partly cut away to show normally hidden detail; and Fig. 4 is a rear view, similarly partly cut away on the right-hand side and the left-hand half of which is shown in section on the line IV-IV in Fig. 3. The mopping unit illustrated comprises a moulded plastics bucket 1, shown mainly in ghost outline in Figs. 1 and 2 so that the operating mechanism is clearly visible, combined with a wringer having two rotatable squeeze rollers 2 and 3 with rotational axes X and Y disposed laterally of, and housed within, the bucket 1. One of the rollers 2 has the position of its axis X fixed in operation adjacent the front of the bucket 1, this position being adjustable as described hereinafter, and the other or rear roller 3 is movable by an operating mechanism 4 between the free "open" wringer position shown in full lines in the drawing figures and the "closed" operative wringer position 3′ illustrated in broken lines. Four corner castors 5 support the bucket 1 raised off the floor. These castors are a push-in fit in moulded sockets such as 5a and may be directly replaced, for use on smooth floors, by stand-off "glider" legs or by other floor support members. A foot-operated pedal 6 of the mechanism 4 is disposed below the roller 2 in a central recess 7 at the front of the bucket 1, a shrouding outer side wall 30 of the bucket being partially cut away in Fig. 3 to show the recess 7 and the mechanism 4. The pedal 6 is connected at its two ends between respective pedal levers 8 and 9 which extend along the two sides of the bucket 1, to which they are pivotally mounted at intermediate pivots 10 and 11. The pivots 10 and 11 are horizontally aligned laterally of the bucket 1. The operating mechanism 4, on depression of the foot pedal 6, moves the rear roller 3 to the operative position 3′ and applies a balanced squeeze pressure through the two ends of that roller, to this end the mechanism 4 employing toggle linkages 12 and 13 duplicated at opposite sides of the bucket 1. At the rear ends the pedal levers 8 and 9 are connected at pivots 14, respectively, to the lower ends of two generally upright plain pivotal links 15 and 16. The upper ends of the links 15 and 16 are connected, by pivots 17 and 18 respectively, to intermediate positions of rear toggle links 19 and 20 of the respective toggle linkages 12 and 13. The toggle links 19 and 20 are mounted at outer ends by fixed aligned pivots 21 and respectively connected at the inner ends, at aligned pivots P, to front toggle links 22 and 23 of the toggle linkages 12 and 13. Opposed pivot mountings 24 and 25 respectively fixed to the toggle links 22 and 23 adjacent the outer ends of these links, at the inner sides thereof, pivotally support the respective ends of the movable roller 3. The roller pivot mountings 24 and 25 are respectively movable along horizontal guide slots such as 26 provided at a top edge region of the bucket 1, to guide the axis Y of the movable roller 3 as it moves between the open position 3 and the operative position 3′. Reference has already been made to adjustability of the front roller 2 whereby to adjust the spacing of the rollers 2 and 3 when in the relatively closed operative position or, looked at another way, to adjust the squeeze pressure on a given mop. To this end a spindle 31 of the roller 2 is mounted so as to be freely rotatable between two adjustment levers 32 and 33 which have a range of angular adjusting movement as indicated in Fig. 3. A series of detent projections such as 34 is moulded on the internal surface of an inner side wall 35 of the bucket 1, at each side of the latter, and these projections are selectively engageable in a moulded recess 36 in the corresponding lever 32 or 33 to retain the latter in an adjusted angular position, which determines the position of the roller axis X, relatively to a moulded pivot boss 37 on which the lever is mounted. Each lever 32 or 33 is retained captive on the corresponding boss 37 by a screw 38 and can rock on that boss 37, against a compression spring 39 disposed between it and the adjacent end of the roller 2, to a position in which it clears the projections 34 to allow adjusting movement of the lever. Thus adjustment of the roller axis X over a shallow arc is provided, this arc being generally aligned with the horizontal slots 26 in side view. Accordingly, in all adjusted positions of the front roller 2 each toggle pivot P, in the operative wringing position of mechanism 4, is substantially coplanar with the roller axes X and Y. To wring out a mop it is inserted into the bucket 1 so as to hang down between the rollers 2 and 3 whilst the latter are in the open position. The foot pedal 6 is then depressed to extend the toggle linkages 12 and 13 and thus move the roller 3 to the closed position 3′. The toggle linkages 12 and 13 are then moved only just overcentre, which position is defined by engagement with a stop provided by the surface of a step in the bucket moulding, so that the links 19 and 22, and 20 and 23, are substantially aligned with the aligned mutual pivots P substantially coplanar with the separate roller axes X and Y. Thus the toggle linkages 12 and 13 effectively act as direct struts to maintain a predetermined spacing of the rollers 2 and 3 to apply the required squeeze pressure to the inserted mop (not shown) which is wrung out as it is pulled upwardly by hand between the rollers 2 and 3. It will be appreciated that foot pressure need be applied to the pedal 6 merely for the time and to the extent necessary to hold down the bucket against the upward pull applied to pull through the mop, the squeeze pressure being determined by the toggle linkages 12 and 13 and not being dependent on foot pressure. At the end of the wringing operation, as the mop leaves the rollers 2 and 3 the toggle linkages are broken by the forces of return springs functionally illustrated in Figs. 1 and 2 as tension springs 28 and 29 anchored to the bucket 1 and respectively connected to the toggle links 19 and 20. In the actual construction these springs are torsion springs such as 40 acting around the respective pivots 21 on the toggle links 19 and 20. The return spring force on each toggle linkage 12 or 13 is not sufficient to move the toggle links back overcentre, and thus to break the toggles, whilst the mop is applying a squeeze pressure reaction to the roller 3. As soon as the mop has left the wringer the springs 28 and 29 are able to return the operating mechanism to the rest position when the foot is removed from the pedal 6. The bucket 1 has a bail-type handle 41 used for carrying purposes. When not in use it pivots rearwardly to lie on top of the bucket where it does not impede the wringing out operation when the wringer rollers 2 and 3 are in use. It will be appreciated from the foregoing description that the invention provides a very simple, efficient and effective roller operating mechanism of a mopping unit. The direct toggle struts provided by the toggle linkages 12 and 13 provide accurate and repeatable roller positioning, and a high squeeze pressure can be applied without flexing of the elements of the operating mechanism affecting operation. A further and manufacturing advantage of the described construction is that the upright links 15 and 16 are the only elements of the operating mechanism which need be changed to suit a different size of bucket. Thus a range of bucket sizes can employ the same mechanism components other than the simple plain links 15 and 16.

Claims: A mopping unit comprising a mop bucket (1) combined with a wringer having two squeeze rollers (2,3) mounted at the top of the bucket, and an operating mechanism for moving one squeeze roller (3) towards and away from the other roller (2), which mechanism includes a toggle linkage (12) connected to the movable roller and comprising two toggle links (19,22) which are directly interconnected at a pivot (P) which, when the two toggle links (19,22) are aligned, is substantially coplanar with the separate rotational axes of the two rollers (2,3), and an operating lever (8) which can be moved to bring the toggle links (19,22) substantially into alignment and thereby bring the movable roller (3) to an operative wringing position, characterised in that the operating lever comprises a foot-operated lever (8) pivotally mounted on a lower part of the bucket (1) and connected by a pivoted link (15) to one (19) of the toggle links, and in that depression of the foot-operated lever (8) displaces the toggle links (19,22) to a limit position, defined by a stop, where they are substantially aligned on opposite sides of said pivot (P) so that they act as a direct strut to support the movable roller (3) in the wringing position, the toggle linkage (12) being slightly overcentre when in said limit position. A mopping unit according to Claim 1, characterised in that the toggle operating mechanism (12,13) is duplicated at the two sides of the bucket, whereby balanced operating forces are applied to the two ends of the movable roller (3). A mopping unit according to Claim 2, characterised in that one toggle link (22,23) of each toggle linkage is directly and pivotally connected to the corresponding end of the movable roller (3). A mopping unit according to Claim 3, characterised in that pivot mountings (24,25) for the movable roller (3) attached to the connected toggle links (22,23) are slidably guided in guide slots (26) along the top edge region of the bucket (1). A mopping unit according to any of Claims 1 to 4, characterised in that said other roller (2) is adjustable so that the spacing of the rollers when in the wringing position, determined by the toggle linkage (12), can be varied to adjust the actual squeeze pressure applied to a mop and said other adjustable roller (2) is rotatably supported between two pivotal adjustment levers (32,33) respectively pivotally supported on the sides of the bucket (1), below the adjustable roller axis, and projecting at the top of the bucket for manual adjustment of the angular position of the levers. A mopping unit according to Claims 4 and 5, characterised in that the axis of the adjustable roller (2) is adjustable over a shallow arc generally aligned with said guide slots (26) in side view. A mopping unit according to Claim 5 or 6, characterised in that detent means to retain each adjustment lever (32,33) in adjusted angular position comprise inter-engageable formations (34,36) on that lever and the corresponding side of the bucket and in that the adjustment levers are mounted within the bucket and are rockable inwardly, against springs (39) disposed between the ends of the adjustable roller (2) and the levers (32,33), on the lever pivot mountings sufficiently to free the detent formations (34,36) and allow angular adjustment of the levers (32,33).

Inventors: TAYLOR MICHAEL, TAYLOR, MICHAEL
Applicants: SCOT YOUNG RESEARCH, SCOT YOUNG RESEARCH LIMITED
Application year: 1989
Main classification: A47L13
IPC codes: A47L13