Cleaning vehicles

Abstract: The vehicle comprises a chamber (38), a duct (36), suction means (164,166) and inlet means (30). The forward portion (102) of said inlet means (30) overlies directly the surface (100) being swept and has a smoothly profiled downwardly facing convex lower air guide surface (104) extending lengthwise of the inlet means in the travel direction (F).

Description: This invention relates to cleaning vehicles comprising matter removal means such as brush gear or suction gear , or both. An example of such a vehicle is a self-propelled cleaning vehicle for cleaning roads and/or runways and/or pavements and/or carrying out industrial cleaning and sweeping , the vehicle having suction gear including a suction nozzle with brush gear in the form of side brushes rotating about upwardly extending axes and serving to sweep matter laterally inwardly into the path of the nozzle (see NL-A-7 114 815). Presently available cleaning vehicles require improvement in respect of the brush gear and suction gear and associated assemblies , particularly their structure , mounting and control. As regards the suction gear , improvements are also needed in respect of the ducts and other assemblies, particularly their structure and arrangement having regard to air flow , power consumption and related factors . An object of the invention is to provide cleaning vehicles , and other apparatus , providing improvements in one or more of these respects ,or generally. According to the invention there is provided a cleaning vehicle as defined in the accompanying claims . Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which : Fig 1 shows a perspective view of a cleaning vehicle as seen from the front and to one side , with the brush gear and suction nozzle turned for a left hand corner ; Fig 2 shows a perspective view of the vehicle of Fig 1 as seen from the rear and one side , with the vacuum tank shown raised to its rear discharge position for emptying into a skip or the like , the steering gear and nozzle being shown turned for a right hand corner ; Fig 3 shows a perspective view from the rear and one side of a suspension assembly forming a front steering unit for the vehicle and a support for the suction nozzle and brush gear ; Fig 4 shows , on a larger scale , a vertical section in the front/rear direction through the suction nozzle and associated structures ; Fig 5 shows a plan view of the left hand half of the nozzle of Fig 4 as viewed in the direction of arrow V in Fig 4 ; Figs 6 and 7 show sections through the nozzle of Fig 5 as indicated by arrows VI - VI and VII - VII in Fig 5 ; Fig 8 shows a side elevation view of the nozzle in the direction indicated by arrow VIII in Fig 5 ; Fig 9 shows an end view of the suction duct of Fig 4 , the direction of viewing being indicated by arrow IX in Fig 4 ; Figs 10 and 11 show , diagrammatically , plan views of the vehicle 10 during sweeping operations into a right-angled corner , and when executing a left-hand turn,respectively ; Figs 12 and 13 show , on a larger scale , one of the brushes of the vehicle of Fig 1 and details of its mounting , the direction of viewing in Fig 12 corresponding approximately to that of Fig 1 , and in Fig 13 being indicated by arrow XIII in Fig 12 ; Fig 14 shows a perspective view of the suction gear including the fan assembly of the vehicle of Fig 2 , the direction of viewing being indicated , approximately by arrow XIV in Fig 2 , this figure also showing , diagrammatically , the positions and approximate dimensions of two plenum chambers , and two vacuum chambers which co-operate with the ducts seen in Fig 14 ; Fig 15 shows an exploded view of one of the fan assemblies seen in Fig 14 ; Fig 16 shows a rear view of part of the vacuum tank assembly of Fig 2 , the direction of viewing being indicated by arrow XVI in Fig 2 ; Fig 17 shows an assembly of two generally L-shaped cab wall elements ; Fig 18 shows a side elevation view of frame elements of the driver's cab of the vehicle of Fig 1 ; Figs 19 , 20 and 21 show sections through a side frame of the cab of the vehicle , the sections being taken in the directions indicated by arrows XIX - XIX , XX - XX , and XXI - XX1 in Fig 18 ; Fig 22 shows the section of Fig 21 on a smaller scale together with an associated sliding window assembly ; Fig 22 shows a section through a crossmember linking the side frames of the cab , the section being taken in the direction indicated by arrows XXII - XXII in Fig 1 ; and Fig 23 shows a vertical section through a modified brush head assembly . SUCTION GEAR - NOZZLE AND SUCTION DUCT The suction gear 26 of vehicle 10 comprises nozzle 30 connected via suction duct 36 to a vacuum tank or chamber to receive matter removed in the cleaning operation. A fan assembly draws the air and entrained matter into the tank and discharges its pressure side to atmosphere. Limitations of existing nozzle and suction duct assemblies include inadequate air flow efficiency , the production of turbulence , consequential high power consumption in the fan assembly , relatively high manufacturing cost , insufficient ability to accommodate large foreign bodies such as soft drink cans , and inadequate resistance to damage upon impact with street furniture and the like. As shown in Figs. 4 to 9 nozzle 30 , constituting matter inlet means , is positionable in close proximity to a surface 100 to be cleaned . The nozzle comprises a moulding of a polymeric material forming a hollow chamber 102 of which the lower surface 104 provides a smoothly profiled upper surface for the front portion of the nozzle. Lower surface 104 of chamber 102 constitutes an air guide surface . All the internal surfaces of nozzle 30 are smoothly profiled to promote efficient air flow . As shown in Fig. 5 the front portion 106 of nozzle 30 has a generally convex shape as seen in plan view . This shape is made up from a central linear section 108 and side sections 110. The result of this convex shape is that the length of the air path over air guide surface 104 between the front edge 108 , 110 of the nozzle and the rear region 112 of the nozzle is of approximately equal length across the full operating width of the nozzle. This is illustrated by the radii 114 shown in Fig. 5 and radiating from point 116 . The throat 118 defined by nozzle 30 and into which air and matter are drawn is defined by air guide surface 104 at the top and by the swept surface 100 below . The lateral extent of the throat is defined by side walls 120 diverging along radii 114 . The throat 118 converges to a nozzle outlet 122 to which is joined the lower end 124 of suction duct 36 . As can be seen in Fig. 5 nozzle outlet 122 and hence lower end 124 of duct 36 are of non-circular cross-sectional profile , being generally rounded and having major and minor axes 126 , 128 respectively , the latter coinciding with the central radius 114 in Fig. 5 . Major axis 126 extends generally transverse to the direction F of normal forward motion of vehicle 10 . It can be seen from Fig. 9that the upper end 130 of duct 36 has a similar cross-sectional profile to its lower end 122 , being generally rounded and having a major axis 132 and a minor axis 134. Both profiles are thus generally oval or elliptical , thereby serving to complement the relatively wide intake width of throat 118 defined by side walls 120 , and enabling relatively large objects such as soft drink cans to pass up the duct 36 without jamming . As shown in Figs. 4 to 7 the structure of nozzle 30 is substantially entirely a hollow body . Chamber 102 forms the front portion thereof . This is integral with the side walls 120 . These latter continue around the rear periphery 136 of the nozzle. As can be seen from Figs. 4,6 and 7, side walls 120 and the rear peripheral portion 136 have a double-skinned structure including a generally flat ground-facing surface 138 . At the rear 136 of the nozzle this lower surface 140 is radiused slightly to accommodate raising and lowering of the nozzle about a lateral axis 142 , under the control of the driver to admit large objects such as soft drink cans. Hollow chamber 102 and throat side walls 120 and rear portion 136 of the nozzle thus form a single hollow structure having considerable structural strength and impact resistance. These structures are formed of a very durable plastics material . The unitary nature of the hollow structure of nozzle 30 gives the latter great structural integrity . The resilient characteristics of the plastics material add to this significant impact resistance and durability . Moreover , the smoothly curved lower profile of rear portion 136 of the nozzle complements the corresponding smooth periphery of the forward and internal portions of the nozzle whereby the relatively small proportion of air entering at the rear of the nozzle does not cause turbulence or otherwise interfere with the smooth air flow. Nozzle 30 is formed by a rotational cr blow moulding technique . This enables the hollow structure to be formed in a cost effective manner . Duct 36 is similarly formed. Its lower portion 124 is detachably fixed to the nozzle. Structural integrity is promoted by a flange 144 formed at the bottom of the duct. The duct may be formed in one or more lengths. Its upper end 130 is mounted on a support 146 and is thus fixed. Nozzle 30 turns with front wheels 16 about steering axis 34 . Thus duct 36 must accommodate a degree of deflection as steering occurs. Its middle portion moves in an arc around axis 34. The nozzle is mounted on support means 28 by fasteners secured to fixing points 148 on the nozzle. The support structure ( not shown ) connecting nozzle 30 to steering axis bearing 150 provides for up and down pivoting of the nozzle about axis 142 under driver control. Such movement is accommodated by flexure of duct 36. For certain applications , it may be preferred to manufacture duct 36 from a resilient material such as rubber , suitably reinforced. In use , the smoothly merging profiles of the nozzle and the suction duct promote efficient air flow along a principal flow path indicated by line 152 in Fig. 4 . The air follows a curved path whereby frictional losses and turbulence are minimised. The generally rectangular oblong cross-sectional shape of throat 118 smoothly merges into the bottom end of suction duct 36 , thereby contributing to minimising air flow efficiency losses . This effect is enhanced by provision of a flared portion 154 of duct 36 at its upper end 130 where it opens into vacuum tank 38. This flared portion of the suction duct acts as a diffuser in which the cross-sectional area of the tube is increased. The kinetic energy of the entrained matter carries it on , but the air is slowed down. In this way kinetic energy of the air is recovered. For example, with a 10% reduction in air velocity , a 20% reduction in power consumption may be achieved. The provision of the convex front edge of the nozzle has the significance that it provides substantially constant path lengths for air entering the nozzle , between the nozzle front edge and the bottom of the suction duct , at all positions across the width of the nozzle. This greatly facilitates non-turbulent air intake . The conventional arrangement with a linear transverse nozzle front edge leads to greatly varying lengths of air flow path through the nozzle , whereby the acceleration effect of the nozzle has varying effects on the air according to its intake location . Hence , different final air speeds are produced with consequential turbulence. Among modifications which could be made in this embodiment without departing from the scope of the invention are the following . Firstly , the front edge 108 of nozzle 30 could be formed with a curved profile instead of the approximation thereto provided by the straight edges in the above embodiment. Considerable variation of the form of the hollow structure of the nozzle may be needed for particular nozzle applications . It may be possible to provide a satisfactory nozzle having two or more closed hollow chambers providing structural members thereof and not forming a single continuous chamber . Although the hollow chamber is generally closed , some opening therein for particular applications may be tolerated without significantly affecting structural integrity . Suitable polymeric materials for manufacture of the nozzle and duct assembly include the following , whether with or without suitable fillers : linear medium density polyethylene (LMDPE),linear high density polyethylene (LHDPE), ultra high density polyethylene ( UHDPE),cross-linked high density polyethylene, Du Pont Hytrel , E.V.A., and others . Suction duct 36 is oval in section throughout its length. It could blend into a larger section cylindrical duct. BRUSH MOUNTING - BRUSH COVERS In the case of matter removal means such as brush gear of a cleaning vehicle it is found that the brush heads are vulnerable to damage , particularly in the case of those mounted on leading arms . Usually , these structures carry drives such as hydraulic motors together with spray nozzles , together with the linkage for supporting the brush head . All these structures are vulnerable to damage upon impact with fixed objects such as street furniture. Previous proposals for meeting these requirements , such as freely rotatable impact plates , have not been found to be adequate , and improvements are required in respect of reduced vulnerability and/or reducing the height requirements of the brush assembly so that the latter can sweep under certain items of street furniture such as seats and--the like. Fig 23 shows details of brush-supporting covers of Fig 1. Figs 12 and 13 show different brush gear supports . As shown in Fig 23 brush 42 comprises bristles 250 mounted on a carrier plate 252 coupled to the output shaft 254 of hydraulic motor 256 driven through hose couplings 258 to effect rotation about axis 60. The motor is located in a housing 260 forming a brush cover and serving to house motor 256 together with spray nozzles 262 located at circumferentally spaced positions along the front periphery of housing 260 to spray water in an arc indicated by line 263 on the forward side of the cone described by bristles 250 . Nozzles 262 receive water from the clean water compartment of tank 167. Housing 260 forms part of the mounting structure for brush 42 and is in the form of a hollow body forming part of the load bearing support structure of the brush. The housing has connection means 264 for direct load-bearing connection to the brush mounting linkage . In this embodiment , the outer portion 202 of the brush mounting arm is rigidly secured to connection means 264 , and the latter is structurally integral with housing 260 , which is formed as a single hollow structure of a suitable plastics material, and serves as a flexible and resilient impact device for collisions of the brush assembly with street furniture such as seats and lamp posts . The hollow plastic structure has internal metal support elements 266 which are directly coupled to the brush mounting linkage . These serve to transfer the brush support loads, to the hollow plastics body 260. However , the major portion of the strength and rigidity of the housing 260 is derived from its own plastics material and the hollow form thereof. The internal metallic structure 266 may be bonded thereto . Openings may be formed in the hollow body sufficient for admission and removal of the motor 256 and its hoses . It will be noted that the brush mounting arm connected to brush 42 extends generally horizontally thereto , and preferably does not project above same by more than about 2.5 centimetres. In use , housing 260 serves to protect motor 256 and nozzles 262 from damage by impacts with fixed objects. The housing adds almost nothing to the overall height of the brush assembly and permits connection of the brush mounting linkage directly to it . Its hollow form gives it significant structural strength whereby the plastics material has sufficient rigidity while retaining the inherent impact resistance of such material , whereby the vulnerability of the brush assembly is greatly reduced. The materials for the construction of housing 260 may be the same synthetic polymers as those for the nozzle 30.

Claims: A cleaning vehicle (10) comprising: a chamber (38) to receive matter removed in a cleaning operation; matter inlet means (30) positionable in close proximity to a surface (100) to be cleaned, to remove matter therefrom; a duct (36) connecting said chamber with said inlet means; suction means (164, 166) in communication with said chamber to draw air and matter through the matter inlet means and through said duct and into said chamber; characterised in that the front portion (106) of said inlet means (30), having regard to the travel direction (F) of the vehicle (10), is generally convex as seen in plan view so that the air path under said front edge of said inlet means to the rear region (112) of the latter which connects same to said duct (36) is of approximately equal length across the full operating width of the inlet means; and the forward portion (102) of said inlet means (30), which directly overlies the surface (100) being swept, and which has a smoothly profiled downwardly facing convex lower air guide surface (104), extends lengthwise of the inlet means in the travel direction (F) throughout a substantial portion of the overall dimension of the inlet means measured in said travel direction, and throughout its lengthwise extent overlies directly the surface (100) being swept and defines therewith a forwardly facing and rearwardly tapering throat in which matter is entrained in the air flow. A cleaning vehicle according to claim 1 characterised in that said matter inlet means (30) has a smooth internal profile with rounded contours, and said duct (36) connecting said chamber to said matter inlet means extends upwardly from said matter inlet means which is adjacent said surface to be cleaned, to a discharge location in said chamber (38), the cross-sectional profile of said duct smoothly merging with that of said matter inlet means (30), and said duct being of non-circular cross-sectional profile throughout a substantial portion of its length up to and including its discharge end (146), the duct being generally rounded in profile and having major (132) and minor (134) axes, the major axis extending generally transverse to the direction (F) of normal forward motion of said vehicle. A cleaning vehicle according to claim 2 characterised in that said duct (36) comprises an outwardly flared portion (154) at its discharge end.

Inventors: DUNCAN IAN JAMES, DUNCAN, IAN JAMES
Applicants: MORNINGFIELD LTD, MORNINGFIELD LIMITED
Application year: 1986
Main classification: E01H1
IPC codes: A47L11, E01H1