EP0039558A2

EP0039558A2 - Sweeper

Info

Publication number: EP0039558A2
Application number: EP81301804A
Authority: EP
Inventors: Michael Edward Gailes
Original assignee: Numatic International Ltd
Current assignee: Numatic International Ltd
Priority date: 1980-04-24
Filing date: 1981-04-23
Publication date: 1981-11-11
Also published as: PT72916B; DK180981A; IE51347B1; ES8301102A1; EP0039558A3; PT72916A; IE810913L; ES502074A0

Abstract

The invention relates to sweepers with particular reference to a ground sweeper having a first sweeper brush of relatively large diameter, a second sweeper brush of relatively small diameter, drive means adapted to drive said first and said second sweeper brush in an opposite sense whereby the said second sweeper brush serves to contact the surface to be swept and wherein the first sweeper brush serves to compliment the second by directing larger objects onto the second brush for collection and transport to said receptacle. The invention particularly describes a manually propelled sweeper in which the first sweeper brush is constructed and arranged whereby beer cans, paper cups and the like are swept into the or onto the second sweeper brush for entrainment and subsequent transport to a collection receptacle.

Description

The present invention relates to a ground sweeper and to rotary brush assemblies for use therein.
Ground sweepers, particularly carpet sweepers have long been known to comprise a wheeled frame for translational movement over a surface to be swept, said frame carrying a dust receptacle and a brush assembly, said assembly being driven by a motor or from gearing associated with at least one of the wheels on which the frame rides during translational movement across a surface to be swept. The brush assembly delivers dirt separately to the dust receptacle by means of a dust conduit which is constituted in part by an elongate opening parallel with the axis of the rotary brush, the lower edge defining said opening being generally in close contact with the remote free ends of the bristles of the respective brush. Such a device will be referred to as a "sweeper of the kind described". These devices are not particularly efficient and have largely been superceded by vacuum cleaners because the transfer of dust and dirt from the rotary brush assemblies to the dust receptacle was largely effected by centrifugal force and this was insufficient in itself to be particularly effective and in the nature of the design only comparatively small objects could be picked-up.
According to the present invention there is provided a sweeper of the kind described comprising,

a first sweeper brush of relatively large diameter,
a second sweeper brush of relatively small diameter; and
drive means adapted to drive said first and second sweeper brushes in an opposite sense, whereby only said second sweeper brush serves to contact the surface to be swept and the first sweeper brush serves to compliment the second by directing larger objects into the second brush for collection and transport to said receptacle.

In a particular aspect of the present invention there is provided an improved sweeper of the type of which includes two counter rotating rotary brushes disposed in parallel juxtaposition, the nature of the brushes and the speed at which they are rotated being sufficient to form a current of entraining air to carry the dust along a single combined entrainment path to the receptacle.
The invention further includes a sweeper having a wheeled frame for translational movement over a surface to be swept, said frame bearing a dust receptacle and a driven pair of juxtaposed rotary brushes the arrangement being such that on translational movement of the frame the brushes counter-rotate to lift dirt and dust along a combined entrainment path to the receptacle.
In one embodiment the second brush may be provided with infill pieces between adjacent lines of bristle to prevent lodgement of debris therebetween.
In another aspect of the invention, the first sweeper brush is a rummage brush comprising substantially continuous brushes or blades which in use have a generally fan effect. The brush may comprise a plurality of radial, circumfentially spaced continuous bristles or may be blades of rubber, plastics or like materials.
In a particular embodiment said brush may comprise an axle, a plurality of linear bristle asemblies radially disposed at equally spaced intervals about the circumference of the said axle, the unsupported length of the bristles exceeding five times or ten times the radius of the axle per se. In a preferred assembly three to five bristle assemblies are provided.
The first and second brushes may be disposed toward the intended front end of the frame, the axles of said brushes being transverse to the intended direction of translational movement.
The bristles of the second or rear brush only may be in brushing contact with the surface to be swept; the remote ends of the bristles of the front brush being arranged to clear the ground so that the front brush acts mainly as a fan to entrain dust and dirt disturbed by the rear brush. Typically, the ground clearance of the first brush is up to 4 inches preferably between ½ inch and 1i inches. In such an arrangement it is preferred that the rear brush rotates at a faster speed than the front brush and in particular it is most preferred that the peripheral speed of the outermost ends of the bristles of the front brush is between 50% and 75% slower than the corresponding peripheral speed of the rear brush.
In a most preferred differential the bristles of the front brush have a peripheral speed of 65% that of the peripheral speed of the bristles of the rear brush.
The front brush is of a larger diameter than the small brush and the linear bristle assemblies thereon may provide sufficient space therebetween to accommodate a beer can or paper cup so that the sweeper of this invention may be used in public places such as parks, railway stations and football grounds.
The rotary brushes may be driven by gearing associated with at least one of the ground contact wheels upon which the frame effects translational movement. The receptacle may be integral with the frame and be provided with a removable lid, but most preferably it is arranged that the receptacle is removable from the frame for emptying as desired.
Following is a description by way of example only and with reference to the accompanying drawings of methods of carrying the invention into effect.
In the drawings:-

Figure 1 is a section through a sweeper in accordance with the present invention.
Figure 2 is a detail of the brush assembly of Figure 1.

A sweeper of the invention is formed of a pair of frame members 1 of substantially rectangular configuration which are spaced apart and adapted to ride substantially perpendicular to the ground. Both frame members are substantially identical and comprise a rear upright 22 terminating at its lower end in a road wheel on a castor assembly 2. A crush bend is formed at the upper end of said rear upright frame member to provide an upper frame member 18 adapted in use to be substantially parallel to the ground. The upper frame member terminates at its forward end in a crush bend through 90° to form a forward frame member 19 substantiaaly perpendicular to the ground in use. The Lower end of the forward frame member 19 terminates in a crush bend to provide a lower frame member 20 parallel to the upper frame member 18 and terminating at its rearend in an angled crush bend to provide angled rear frame member 21 to which handle 4 is attached. The frame members 1 are spaced apart by means of spacing members provided at each crush bend.
Disposed between the two parallel frame members 1 is a removable dust receptable 6 having a cover 5 and terminating at its forward end in a dust slot 17 constituting a substantially horizontally disposed slot through which entrained dust passes from the brushes to the receptacle. The lower horizontal edge of the dust slot 17 is angled forwardly to form a lower deflector plate 15.
Disposed forwardly of the dust slot 17 is an upper deflector plate 14 which forms with the lower deflector plate 15 a passage through which dust can pass. The upper deflector plate 14 is carried on the undersruface of a brush cover 13 which extends from the receptacle cover 5 to the forward edge of the sweeper and thence downwardly against and about forward frame member 19 to a position approaching half-way between the upper frame member 19 and the lower frame member 20.
A pair of paddle wheel brushes 7 and 8 are disposed in the space between the forward frame member 19 and the receptacle 6. These rotary brushes have parallel axles 11 and 12 respectively, each journalled at their remote ends for rotation in bearing assemblies (not shown). Both axles are driven by a gearing assembly associated with forward road wheels (which gear train has been omitted since it is of standard form). The gear train is so arranged that at a translational speed of 1 mile per hour the larger brush 7 rotates at 220 rpm., and the smaller brush rotates at 660 rpm. while the main driving wheel rotates at 39 rpm.
The small rotary paddle wheel brush 8 comprises 4 bristle assemblies 10' the bristle assembly having a free unsupported length approximately 5 times the diameter of the axle. The axle 12 is adjustable vertically so as to bring the remote ends of the bristles 10' into scrubbing contact with the ground 9.
It will be appreciated that by virtue of this adjustment the axle 12 may be adjusted downwardlyaid slightly forwardly for wear occasioned by the scrubbing action of the bristles on the ground. In a preferred embodiment of this type the lower deflector plate 15 is vertically slotted along its length and held in position by suitable nut and bolt assemblies whereby it may be moved vertically with the axle 12 in order that the deflector plate 15 is always correctly positioned.
The small paddle wheel brush 8 may be further provided between adjacent bristle assemblies 10' with an insert piece 30 is shown in greater detail in Figure 2. The insert piece comprises an arcuate outer portion 31 a pair of radial edge walls 32 and a recessed portion 33 provided towards the inter extremity of the insert portion. The insert portion 30 is formed as an extrusion of a plastics material and the longitudinal side walls 32 can be sprung inwardly so that the recess 33 engages a corresponding projection (not shown) along the base of each bristle assembly 10'.
In operation debris lifted by bristles 10 of the forward brush assemblies 7 can be carried by bristles 10' and associated in said portion 30 without the debris becoming jammed within the quandant between adjacent bristle assemblies 10' and is then carried over a threshold guide 15 into receptical 6.
The large rotary paddle wheel brush 7 has four bristle assemblies 10 equally spaced about the circumference of the axle 11. The unsupported length of the bristle assembly 10 is approximately ten times the diameter of the axle 11 and the remote ends of the bristle assembly 10 are arranged to rotate just clear of the ground surface 9. Since the paddle wheel 7 rotates against the direction of translational movement of the sweeper and because of the large spaces provided between the bristle assemblies 10 items such as paper cups and beer cans can pass under the cover 13 and become lodged between adjacent bristle assemblies 10. Such items are then propelled mainly by centrifugal force into the dust receptacle 6, usually contacting the upper deflector plate 4 en route. Although means for vertical and horizontal adjustment of the axle 11 may be provided, this is not so necessary as it is for brush 8 since the remote ends of the bristle assemblies 10 do not wear to the same extent.
In use an operative grasps the handle 4 and propels the sweeper over the ground to be swept. In an alternative embodiment an internal combustion engine or an electric motor may be incorporated either to drive either the brushes only or to supply power to the driven road wheels. In the latter case, means may be provided whereby the operative may ride upon the vehicle which is then self-powered.
As the device moves translationally across the surface to be swept the outer ends of the bristle assembly 10' of the small paddle wheel brush 8 contact the ground and throw the dust and dirt upwardly and forwardly. Simultaneously the larger paddle wheel 7 creates a comparatively large current of air flowing substantially horizontally and backwardly. As the two air flows coalesce at a point above the small paddle wheel 8 the air is compressed and thereby increases in speed. Dust and dirt disturbed by the bristles 10' is thereby entrained in this combined air flow and deposited in the dust receptacle 6. It will immediately be seen that by virtue of the coalesced air streames much heavier particles then heretofor can be entrained and hence the sweeper is more efficient than those known previously.
The large brush 7 does not contact the ground 9 and acts essentially to provide vigorous air flow to the dust receptacle 6. However, as stated before it will also act to pick up larger objects such as beer cans and paper cups and compel them, mainly by centrifugal force into the dust receptacle 6. When the dust receptacle approaches full the operator merely removes it to a convenient site and empties it in the usual fashion. It may then be replaced and the sweeping process continued. If a particularly large item becomes jammed under the brush cover 13 it is simple to remove the brush cover 13 and clear the obstruction.
It has been found that the sweeper in accord with the invention has been particularly useful for use in public places such as Sports grounds and railway termini etc., but of course smaller versions may be useful domestically.

Claims

1. A sweeper of the kind described comprising a first sweeper brush of relatively large diameter, a second sweeper brush of relatively small diameter and drive means adapted to drive said first and second sweeper brushes in an opposite sense whereby only the second sweeper brush serves to contact the surface to be swept and the first sweeper brush serves to compliment the second sweeper brush by directing larger objects into the second brush for collection and transport to said receptacle.

2. A sweeper as claimed in claim 1 wherein first and second brushes are disposed in parallel juxtaposition and are constructed and arranged to provide a current of air to carry the dust along a single path to said receptacle.

3. A sweeper as claimed in claim 1 or claim 2 including a wheeled frame for translational movement over a surface to be swept, said frame carrying a dust receptacle and said first and said second sweeper brushes in juxtaposition thereto, the arrangement being such that on translational movement of the frame, the brush is counter-rotated to lift dirt and dust along said path to said receptacle.

4. A sweeper as claimed in any preceding claim wherein the second sweeper brush is provided with infilled pieces between adjacent lines of bristles to prevent lodgement of debris therebetween.

5. A sweeper as claimed in any one of the preceding claims wherein the first sweeper brush comprises a plurality of substantially continuous blades or bristles in the form of a paddle wheel which in use provides an air current and serves as a rumage brush for directing debris into the path or onto the counter-rotating bristles of said second brush.

6. A sweeper as claimed in claim 5 wherein each brush comprises a plurality of linear bristle assemblies which are radially disposed symmetrically about the circumference of the brush axle wherein the unsupported length and bristles is between 5 and 10 times the radius of the axle per se.

7. A sweeper as claimed in claim 6 wherein three to five bristle assemblies or blades are provided for each brush.

8. A sweeper as claimed in any preceding claim wherein the bristles of the second brush are in brushing contact with the surface to be swept, the remote ends of the bristles of the front brush being arranged to clear the ground so that the front brush acts mainly as a fan or paddle wheel to entrain dust and dirt disturbed by the rear brush.

9. A sweeper as claimed in any preceding claim wherein the ground clearance of the first brush is within the range of i inch to 4 inches from the arc defined by the bristle extremities to the surface to be swept.

10. A sweeper as claimed in any preceding claim wherein the peripheral speed of the bristles of the second brush are greater than the peripheral speed of the first brush.

11. A sweeper as claimed in any preceding claim wherein the ground clearance of said first brush is inch to 1½ inch measured from the arc defined by the bristle extremities to the surface to be swept.