WO2009006667A1 - Discharge chute for a concrete truck and method of manufacturing same - Google Patents

Discharge chute for a concrete truck and method of manufacturing same Download PDF

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Publication number
WO2009006667A1
WO2009006667A1 PCT/AU2007/001773 AU2007001773W WO2009006667A1 WO 2009006667 A1 WO2009006667 A1 WO 2009006667A1 AU 2007001773 W AU2007001773 W AU 2007001773W WO 2009006667 A1 WO2009006667 A1 WO 2009006667A1
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WO
WIPO (PCT)
Prior art keywords
discharge chute
discharge
disposed
polymeric material
convex outer
Prior art date
Application number
PCT/AU2007/001773
Other languages
French (fr)
Inventor
David Sheridan
Graeme Dahlstrom
Original Assignee
Dahlsher Pty Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2007903793A external-priority patent/AU2007903793A0/en
Application filed by Dahlsher Pty Limited filed Critical Dahlsher Pty Limited
Publication of WO2009006667A1 publication Critical patent/WO2009006667A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
    • B65G11/00—Chutes
    • B65G11/18—Supports or mountings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28C5/00—Apparatus or methods for producing mixtures of cement with other substances, e.g. slurries, mortars, porous or fibrous compositions
    • B28C5/42—Apparatus specially adapted for being mounted on vehicles with provision for mixing during transport
    • B28C5/4203—Details; Accessories
    • B28C5/4234—Charge or discharge systems therefor
    • B28C5/4244—Discharging; Concrete conveyor means, chutes or spouts therefor
    • B28C5/4248—Discharging; Concrete conveyor means, chutes or spouts therefor using chutes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
    • B65G11/00—Chutes
    • B65G11/08—Chutes with discontinuous guiding surfaces, e.g. arranged in zigzag or cascade formation
    • B65G11/083—Chutes with discontinuous guiding surfaces, e.g. arranged in zigzag or cascade formation for bulk

Definitions

  • the present invention relates, generally, to apparatus for mixing, transporting and/or dispensing concrete and relates particularly, though not exclusively, to discharge chutes for guiding premixed concrete from concrete agitator drums to desired construction sites. More particularly, the present invention relates to an improved discharge chute for a concrete truck that is comparatively light and is substantially more durable than a conventional metallic discharge chute. In a further aspect, the present invention also relates to methods for manufacturing these improved discharge chutes.
  • Concrete mixing trucks are widely used in the construction industry for transporting and dispensing premixed concrete.
  • Conventional concrete trucks include vehicle mounted agitator drums that provide a storage area for transporting concrete in an unset state.
  • a plurality of discharge chutes are attached to these vehicle mounted agitator drums. These discharge chutes allow the concrete to be guided from the agitator drum to a desired pour area. If a number of discharge chutes are interconnected to one another, the distance that the concrete can be delivered may be extended.
  • plastics or other polymeric material liners have been introduced that provide a smooth and durable guide surface during use. These types of liners are mechanically fastened to the frame of a metallic chute and generally conform to the internal concave guide surface of same. Although successful at extending the life of a metallic chute in terms of ensuring that the guide surface remains relatively smooth and unhindered, the overall discharge chute is still prone to other forms of damage and wear as a result of its metallic construction.
  • said elongated body, said skeletal frame structure, said supply end connecting means and said discharge end connecting means are a single conjoint component constructed of the same polymeric material.
  • said discharge end connecting means are separate components that are mechanically fastened to said discharge chute.
  • said supply end connecting means are hook-type couplings that enable said discharge chute to be removably and pivotably mounted to cooperating couplings disposed on said discharge end of said vehicle mounted agitator drum.
  • said cooperating couplings are loop-type couplings that enable said discharge chute to be suspended thereon by way of said hook-type couplings.
  • said discharge end connecting means are the same or similar loop-type couplings to those disposed on said discharge end of said vehicle mounted agitator drum, such that a further discharge chute having suitable hook-type couplings disposed on a supply end thereof can be selectively suspended thereon.
  • said skeletal frame structure includes a plurality of longitudinal stiffening bars, and at least one lateral stiffening rib. It is also preferred that skeletal frame structure includes at least five longitudinal stiffening bars and at least two lateral stiffening ribs. In a practical preferred embodiment, said skeletal frame structure includes at least one lateral stiffening rib disposed at, or near, each of said supply and discharge ends of said elongated body. In this practical preferred embodiment, it is preferred that said lateral stiffening ribs are disposed substantially in parallel to their respective supply or discharge end of said elongated body.
  • At least two of said at least five longitudinal stiffening bars are diagonally disposed relative to respective open sides of said convex outer surface. It is also preferred that all remaining longitudinal stiffening bars of said skeletal frame structure are disposed substantially in parallel to said open sides of said convex outer surface.
  • each of said longitudinal stiffening bars disposed in parallel to said open sides of said convex outer surface one is disposed generally at an apex of said convex outer surface of said elongated body, and the others are each disposed at, or near, a respective open side of said convex outer surface. It is also preferred that one end of each of said longitudinal stiffening bars that are diagonally disposed relative to said open sides of said convex outer surface are connected to said longitudinal stiffening bar disposed at said apex of said convex outer surface.
  • said polymeric material is polyurethane.
  • said polyurethane is a rigid polyurethane having a set hardness of 74 Shore D, preferably Adiprene LF750D.
  • a method for manufacturing a discharge chute for guiding a concrete mixture from a discharge end of a vehicle mounted agitator drum to a predetermined pour area said discharge chute including: an elongated body defining a substantially concave inner guide surface and a substantially convex outer surface which is generally concentric with said inner guide surface; a skeletal frame structure disposed on said convex outer surface of said elongated body for reinforcing said discharge chute against operational stresses; and, connecting means disposed at a supply end of said elongated body for attaching said discharge chute to said discharge end of said vehicle mounted agitator drum; wherein said elongated body, said skeletal frame structure and said connecting means are a single conjoint component constructed of a polymeric material; and wherein said method includes the steps of: heating said polymeric material to a predetermined moulding temperature; gravity feeding said heated polymeric material into a mould having integral skeletal frame structure channels and means for forming said connecting means; allowing said polymeric material to cool
  • said discharge chute further includes connecting means disposed at a discharge end of said elongated body for selectively, and removably, attaching said discharge chute to a further discharge chute or chutes.
  • said mould further includes means for forming said discharge end connecting means.
  • said discharge chute includes non-polymeric material inserts, preferably constructed of a metallic material, disposed relative to said supply end connecting means for reinforcing same.
  • said method further includes the step of positioning said inserts within said mould prior to said heated polymeric material being gravity fed therein, such that said metal inserts are set into, and disposed internally of, said polymeric material relative to said supply end connecting means after said predetermined cooling time.
  • said method further includes the step of cleaning and/or polishing any excess material off said discharge chute after said chute has been cured.
  • said polymeric material is polyurethane.
  • said polyurethane is a rigid polyurethane, preferably Adiprene LF750D, having a set hardness of 74 Shore D.
  • Fig. 1 is a discharge end perspective view of a discharge chute for a concrete truck made in accordance with a first preferred embodiment of the present invention
  • Fig. 2a is a right side view of the discharge chute shown in Fig. 1 , the discharge chute shown partly in cross-section to illustrate the addition of preferred metal inserts which may be used to reinforce the hook-type couplings disposed at the supply end of the discharge chute;
  • Fig. 2b is a perspective view of one of the preferred metal reinforcing inserts shown in cross-section in Fig. 2a;
  • Fig. 3 is a supply end perspective view of the discharge chute shown in Fig. 1 , the discharge chute again shown partly in cross-section to illustrate the addition of the preferred metal reinforcing inserts shown in Fig. 2b;
  • Fig. 4 is a left side view of the discharge chute shown in Fig. 1 ;
  • Fig. 5 is a plan view of the discharge chute shown in Fig. 1 ;
  • Fig. 6 is an underneath view of the discharge chute shown in Fig. 1 ;
  • Fig. 7 is an underneath view of a discharge chute for a concrete truck made in accordance with a second preferred embodiment of the present invention.
  • Fig. 9 is a supply end perspective view of a plurality of discharge chutes interconnected to one another, each of the discharge chutes being the same or similar to any one of the discharge chutes shown in Figs. 1 to 8;
  • Fig. 10a is a cross-sectional end view of a preferred three-piece casting mould which may be used to construct any one of the discharge chute shown in Figs. 1 to 8 in accordance with a preferred method of manufacturing a discharge chute;
  • Fig. 10b is a plan view of one part of the two-part convex producing section of the three-part mould shown in Fig. 10a; and,
  • Fig. 11 is a perspective view illustrating a procedural step of the preferred method of manufacturing a discharge chute in accordance with the present invention.
  • discharge chute 10 may be utilised to guide many other forms of materials being dispensed from many other forms of equipment, and as such the present invention is not limited to the specific example provided.
  • Discharge chute 10 includes an elongated body 12 constructed entirely of a polymeric material and having a substantially concave inner guide surface 14 and a substantially convex outer surface 16 which is generally concentric with inner guide surface 14.
  • a skeletal frame structure 18 Disposed on convex outer surface 16 of elongated body 12 is a skeletal frame structure 18 which is also constructed of a polymeric material, and which is provided to reinforce discharge chute 10 against operational stresses caused by the weight of the premixed concrete applied to discharge chute 10 during use.
  • skeletal frame structure 18 includes a plurality of longitudinal stiffening bars 20i ... 2O n , and a plurality of lateral stiffening ribs 22i ... 22 n , that together form a rigid framework that provides the necessary strength to discharge chute 10.
  • skeletal frame structure 18 includes five longitudinal stiffening bars 201,202,203,204,2O 5 , and two lateral stiffening ribs 22 ⁇ 2 . Referring to Fig. 6, it can be seen that all five longitudinal stiffening bars
  • 20i ,20 2 ,20 3 ,20 4 ,20 5 extend from, or near, supply end s of discharge chute 10 and terminate at, or near, discharge end of thereof.
  • Three 20i,2 ⁇ 2 ,2 ⁇ 3 ⁇ f the five longitudinal stiffening bars 20i,20 2 ,20 3 ,20 4 ,20 5 run end-to-end relative to supply and discharge ends s,d of discharge chute 10. Whilst the remaining two 20 4 ,2O 5 longitudinal stiffening bars run diagonally across convex outer surface 16 of elongated body 12.
  • longitudinal stiffening bars 20 4 ,20 5 help to prevent flexing and/or twisting of discharge chute 10 during use and for this reason longitudinal stiffening bars 20 4 ,20 5 of skeletal frame structure 18 are important to the construction of discharge chute 10.
  • One 2O 2 of the three 20i,20 2 ,20 3 longitudinal stiffening bars that run end- to-end relative to supply and discharge ends s,d of discharge chute 10 is disposed generally at the apex of convex outer surface 16 of elongated body 12, whilst the remaining two 20i,2 ⁇ 3 longitudinal stiffening bars are each disposed at, or near, a respective open side of convex outer surface 16.
  • stiffening ribs 22i,22 2 of skeletal frame structure 18 are generally disposed in parallel to their respective supply or discharge ends s,d of discharge chute 10.
  • a pair of hook-type couplings 24i,24 2 Disposed at supply end s of discharge chute 10 is a pair of hook-type couplings 24i,24 2 that are also constructed of a polymeric material, and that are each preferably formed integral with a respective longitudinal stiffening bar 20i,20 3 .
  • Supply end s hook-type couplings 24i,24 2 enable discharge chute 10 to be removably and pivotably mounted to cooperating loop-type couplings (not shown) disposed on the discharge end of a vehicle mounted agitator drum (not shown).
  • the cooperating loop-type couplings disposed on the discharge end of an agitator drum enable discharge chute 10 to be suspended thereon by way of hook-type couplings 24i ,24 2 .
  • each of longitudinal stiffening bars 20i,20 3 may be provided with a metal (hook-shaped) reinforcing insert 26i,26 2 that is disposed internally of the polymeric material used to construct hook-type couplings 24i,24 2 .
  • metal inserts 26i,26 2 is proposed as a means of strengthening discharge chute 10 relative to hook-type couplings 24i,24 2 , it should be appreciated that same may not be required should the polymeric material used to construct discharge chute 10 be sufficiently thick, relative to hook-type couplings 24i,24 2 , to withstand operational stresses relative thereto.
  • elongated body 12, skeletal frame structure 18 and hook-type couplings 24i,24 2 of discharge chute 10 are preferably a single conjoint component constructed of the same polymeric material utilising a suitable casting technique. A preferred method of manufacturing a discharge chute 10 in accordance with the present invention will be provided later in this description.
  • discharge chute 10 In terms of the polymeric material used to construct discharge chute 10, it is preferred that same has a low frictional characteristic which results in a high operational efficiency in terms of the premixed concrete being dispensed via concave inner guide surface 14 of discharge chute 10. It is also preferred that the selected polymeric material has superior wear resistant properties as compared to that of the materials used to construct conventional metallic discharge chutes (not shown), resulting in an extended operational lifetime.
  • polyurethane is that distributed under the trade name
  • a pair of loop-type couplings 28 1 ,28 2 that are disposed at discharge end d of discharge chute 10, and which are each preferably formed integral with, or are affixed to, a respective longitudinal stiffening bar 20i,20 3 of skeletal frame structure 18.
  • Loop-type couplings 28 1 ,28 2 are preferably constructed of the same polymeric material to that used to construct the remaining conjoint polymeric material components 12,18,24 of discharge chute 10, but may alternatively be constructed of a different material, such as, for example metal. If constructed of the same polymeric material, it is preferred that elongated body 12, skeletal frame structure 18, hook-type couplings 24i,24 2 , and loop-type couplings 28i,28 2 of discharge chute 10 are a single conjoint component constructed of the same polymeric material utilising a suitable casting technique.
  • loop-type couplings 28 1 ,28 2 may be set into longitudinal stiffening bars 20i,20 3 of skeletal frame structure 18 during the casting process, or may be mechanically fastened to same after the conjoint polymeric material components 12,18,24 of discharge chute 10 have been produced.
  • Discharge end d loop-type couplings 281,282 which may be the same as, or similar to, the cooperating loop-type couplings (not shown) disposed on the discharge end of a vehicle mounted agitator drum (not shown), enable discharge chute 10 to be selectively, and removably, attaching to a further discharge chute(s) 10 (see Fig. 9).
  • Loop-type couplings 28i,28 2 also provide convenient handles to assist with moving and/or positioning discharge chutes 10 during use.
  • FIGs. 7 & 8 there is shown a discharge chute 100, made in accordance with a second preferred embodiment of the present invention.
  • discharge chute 100 may be utilised to guide many other forms of materials being dispensed from many other forms of equipment, and as such the present invention is not limited to the specific example provided.
  • like reference numerals correspond to like parts shown in Figs. 1 to 6.
  • Discharge chute 100 of Figs. 7 & 8 varies to that of discharge chute 10 of Figs. 1 to 6, only in respect of the rigid framework design of skeletal frame structure 118. More particularly, when compared with discharge chute 10 of Figs. 1 to 6, it can be seen that skeletal frame structure 118, of discharge chute 100, includes an additional two diagonal longitudinal stiffening bars 12O 6 , 12O 7 , which provide added reinforcement to discharge chute 100 during use.
  • each of these additional diagonal longitudinal stiffening bars 120 6 ,120 7 run from, or near, supply end s of discharge chute 100, and terminate at, or near, the apex of convex outer surface 116 (and the longitudinal stiffening bar 12O 2 disposed thereon), at a point which is intermediate of supply and discharge ends s,d of discharge chute 100.
  • discharge chute 100 provides even greater resistance to flexing and/or twisting during use.
  • FIG. 9 there is shown three discharge chutes 10 or 100 interconnected with one another by way of cooperating hook- and loop-type couplings 24i or 124!,1242,1281,12S 2 , disposed on respective supply and discharge ends s,d of discharge chutes 10,100.
  • This figure demonstrates that any suitable number of discharge chutes 1O n , 10O n made in accordance with the present invention can be interconnected with one another to increase the distance over which premixed concrete may be delivered.
  • discharge chutes 10,100 are so designed that the next chute 10,100 will fit under the first chute 10,100 in an overlap fashion. Referring particularly to the left- and right-hand side views of Figs. 2a,4 & 8, it can be seen that discharge end d of elongated body 12,112 is raised relative to its supply end s thereof. In this way, elongated body 12,112, at supply end s of a further discharge chute 10,100 (not shown in Figs.
  • the preferred manufacturing method of the present invention utilises a mould 30 for casting a polymeric material discharge chute 10,100 having conjoint chute components 12,18,24,28 or 112,118,124,128, namely, elongated body 12,112, skeletal frame structure 18,118, hook-type couplings 24- ⁇ ,24 2 or 124i,124 2 , and loop-type couplings 28i,28 2 or 128L1282.
  • FIG. 10a A suitable mould 30 for casting a polymeric material discharge chute 10,100 made in accordance with the present invention is shown in Fig. 10a.
  • Mould 30 is a three-part casting mould having a one-piece section 32 for forming concave inner guide surface 14,114 of discharge chute 10,100, and two separate sections 34,36, each for forming a part, preferably half, of convex outer surface 16,116 of discharge chute 10,100.
  • Mould 30 may be constructed of any suitable material, but is preferably constructed of fibreglass or aluminium.
  • the two convex outer surface 16,116 forming sections 34,36 of mould 30 incorporate the required crevices or channels 220i ... 220 n ,222i ... 222 n , necessary to produce longitudinal stiffening bars 20i,120i ... 2O n , 12O n , and lateral stiffening ribs 22 1 ( 122i ... 22 n ,122 n of skeletal frame structure 18,118 (combined skeletal frame structure forming channels 218 as shown in Fig. 10a).
  • convex outer surface 16 forming section 34, of mould 30 of Fig. 10b is specifically configured to be used to produce discharge chute 10 of Figs. 1 to 6.
  • mould 30 of Figs. 10a & 10b may include any suitable number of channels 220i ... 220 n ,222i ... 222 n , necessary to produce a skeletal frame structure 18,118 having any suitable number of longitudinal stiffening bars 20i,120i ... 2O n , 12O n , and lateral stiffening ribs 22i,122i ... 22 n) 122 n , depending on the requirements of the chute being produced.
  • mould 30 may include dual diagonal channels 22On on each of convex outer surface 16,116 forming sections 34,36, in order to produce a discharge chute 100 made in accordance with the second preferred embodiment shown in Figs. 7 & 8. The present invention should therefore not be construed as limited to the specific example provided.
  • mould 30 also includes the necessary means for forming hook- and loop-type couplings 24i,242,28i,28 2 or 124i,124 2 ,128i,128 2 of discharge chute 10,100. Similarly, although not shown, it should be appreciated that mould 30 may also include any necessary means for positioning reinforcing metal inserts 26i,26 2 or 126i,1262 within mould 30 prior to the polymeric construction material (not shown) being introduced therein.
  • opening 42 In order to enable the polymeric construction material (not shown) to be introduced into gap 40 provided within mould 30, at least one opening 42 (see, for example, Fig. 11) is provided in at least one of separate sections 32,34,36 of mould 30. Opening(s) 42 enables a polymeric material dispensing tool or funnel 44 to be inserted therein in order to gravity feed the required amount of polymeric material into mould 30 in accordance with the preferred method of manufacture of the present invention, which will now be described.
  • the preferred method of manufacturing a discharge chute 10,100 made in accordance with the present invention includes at least the following steps: heating a polymeric construction material to a suitable moulding temperature, the actual moulding temperature depending on the specific polymeric material used; gravity feeding the heated polymeric construction material into a mould 30 via opening(s) 42; allowing the heated polymeric construction material to cool for a predetermined cooling time within mould 30 such that discharge chute 10,100 is formed, the actual cooling time depending on the specific polymeric material used; removing discharge chute 10,100 from mould 30 after the predetermined cooling time; and, curing discharge chute 10,100 in an oven (not shown) for a predetermined curing time at a predetermined curing temperature, the actual curing time and curing temperature depending on the specific polymeric material used.
  • polymeric construction material Any suitable polymeric construction material may be used, however it is preferred that the polymeric construction material is polyurethane.
  • a preferred polyurethane is that distributed under the trade name "Adiprene LF750D", which is commonly known as rigid polyurethane, and which has a set hardness of 74 Shore D.
  • the predetermined cooling time is at least ten minutes, and the predetermining curing time is at least sixteen hours at a predetermined curing temperature of 110 degrees Celsius. If it is desired to produce a discharge chute 10,100 having reinforcing metal inserts 261,262 or 126i,1262, cast internally of discharge chute 10,100 relative to supply end s hook-type couplings 24i,24 2 or 124i,124 2 the preferred method of manufacture of the present invention further includes the step of: positioning the reinforcing metal inserts 26 1 ,26 2 or 126i,126 2 within mould 30 prior to the heated polymeric material being gravity fed therein.
  • a discharge chute 10,100 manufactured in accordance with the preferred method of the present invention may require some form of cleaning and/or polishing in order to ensure that at least the concave inner guide surface 14,114 of discharge chute 10,100 is smooth and ready for use. If such is desired, the preferred method of manufacture of the present invention may also include the step of: cleaning and/or polishing any excess construction material off discharge chute 10,100 after same has been cured.
  • the present invention therefore provides a useful discharge chute 10,100 for a concrete truck, and a method for manufacturing same, that can be used as an alternative to a conventional metallic discharge chute, and which is relatively light and is substantially more durable when compared thereto.
  • a resultant discharge chute can be up to 60% lighter than a conventional metallic chute of similar design.
  • the discharge chute of the present invention also offers far superior operational resistance to wear and damage due to its non-metallic construction.
  • Discharge chutes made in accordance with the present invention have been found to be extremely durable and long-wearing. Under test conditions, it was found that the severe impact caused by a vehicle reversing over a test discharge chute did not damage the chute due to the structural memory provided by the polymeric material used to construct same. This structural memory causes the chute to revert to its original shape once the impact pressure is released.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Structural Engineering (AREA)
  • Chutes (AREA)
  • Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)

Abstract

The present invention provides a discharge chute (10,100) for guiding a concrete mixture from a discharge end of a vehicle mounted agitator drum to a predetermined pour area. The discharge chute (10,100) including: an elongated body (12,112) defining a substantially concave inner guide surface (14,114) and a substantially convex outer surface (16,116) which is generally concentric with the inner guide surface (14,114); a skeletal frame structure (18,118) disposed on the convex outer surface (16,116) of the elongated body (12,112) for reinforcing the discharge chute (10,100) against operational stresses; and, connecting means (24,124) disposed at a supply end (s) of the elongated body (12,112) for attaching the discharge chute (10,100) to the discharge end of the vehicle mounted agitator drum. Wherein the elongated body (12,112), the skeletal frame structure (18,118), and the connecting means (24,124) are a single conjoint component constructed of a polymeric material. In a further aspect, the present invention also provides a method for manufacturing the discharge chutes (10,100).

Description

DISCHARGE CHUTE FOR A CONCRETE TRUCK AND METHOD OF
MANUFACTURING SAME
TECHNICAL FIELD The present invention relates, generally, to apparatus for mixing, transporting and/or dispensing concrete and relates particularly, though not exclusively, to discharge chutes for guiding premixed concrete from concrete agitator drums to desired construction sites. More particularly, the present invention relates to an improved discharge chute for a concrete truck that is comparatively light and is substantially more durable than a conventional metallic discharge chute. In a further aspect, the present invention also relates to methods for manufacturing these improved discharge chutes.
It will be convenient to hereinafter describe the invention in relation to a discharge chute for a concrete truck, however it should be appreciated that the discharge chute of the present invention is not limited to that use only.
BACKGROUND ART
Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms a part of the prior art base or the common general knowledge in the relevant art in Australia or elsewhere on or before the priority date of the disclosure herein.
Concrete mixing trucks are widely used in the construction industry for transporting and dispensing premixed concrete. Conventional concrete trucks include vehicle mounted agitator drums that provide a storage area for transporting concrete in an unset state. In order to dispense the premixed concrete at a desired construction site, a plurality of discharge chutes are attached to these vehicle mounted agitator drums. These discharge chutes allow the concrete to be guided from the agitator drum to a desired pour area. If a number of discharge chutes are interconnected to one another, the distance that the concrete can be delivered may be extended.
As a result of the inherent stresses applied to discharge chutes during use, conventional chutes have been fabricated entirely from steel or aluminium to provide the strength required to withstand the weight of premixed concrete. Although metallic chutes have proven to be effective at guiding premixed concrete from an agitator drum to a pour area, they have been found to be prone to wear and can be easily damaged during use. Like any other form of metal component, metallic discharge chutes have a tendency to oxidise or corrode after prolonged use. This form of deterioration, combined with normal wear and tear, reduces the effectiveness of metallic chutes and inevitably leads to replacement of those components.
In an attempt to extend the operational life of metallic discharge chutes, plastics or other polymeric material liners have been introduced that provide a smooth and durable guide surface during use. These types of liners are mechanically fastened to the frame of a metallic chute and generally conform to the internal concave guide surface of same. Although successful at extending the life of a metallic chute in terms of ensuring that the guide surface remains relatively smooth and unhindered, the overall discharge chute is still prone to other forms of damage and wear as a result of its metallic construction.
Notwithstanding the disadvantages discussed above, the attachment of a liner to the concave guide surface of a conventional discharge chute does not alter an obvious disadvantage associated with the use of metallic chutes, that is, metallic chutes are heavy and cumbersome which makes them difficult to move and position during use. With the tightening of operational health and safety requirements throughout the developed world, the weight of conventional metallic discharge chutes is believed to be a serious issue that has yet to be successfully addressed. A need therefore exists for a quality alternative discharge chute for a concrete truck, one that is comparatively light and is substantially more durable than a conventional metallic discharge chute.
It is therefore an object of the present invention to provide an improved discharge chute for a concrete truck. It is a further object of the present invention to provide a method of manufacturing the improved discharge chutes of the present invention. DISCLOSURE OF THE INVENTION
According to one aspect of the present invention there is provided a discharge chute for guiding a concrete mixture from a discharge end of a vehicle mounted agitator drum to a predetermined pour area, said discharge chute including: an elongated body defining a substantially concave inner guide surface and a substantially convex outer surface which is generally concentric with said inner guide surface; a skeletal frame structure disposed on said convex outer surface of said elongated body for reinforcing said discharge chute against operational stresses; and, connecting means disposed at a supply end of said elongated body for attaching said discharge chute to said discharge end of said vehicle mounted agitator drum; wherein said elongated body, said skeletal frame structure and said connecting means are a single conjoint component constructed of a polymeric material.
Preferably said discharge chute further includes connecting means disposed at a discharge end of said elongated body for selectively, and removably, attaching said discharge chute to a further discharge chute or chutes.
In a practical preferred embodiment, said elongated body, said skeletal frame structure, said supply end connecting means and said discharge end connecting means are a single conjoint component constructed of the same polymeric material. In an alternative practical preferred embodiment, said discharge end connecting means are separate components that are mechanically fastened to said discharge chute.
In a practical preferred embodiment, said supply end connecting means are hook-type couplings that enable said discharge chute to be removably and pivotably mounted to cooperating couplings disposed on said discharge end of said vehicle mounted agitator drum. Preferably said cooperating couplings are loop-type couplings that enable said discharge chute to be suspended thereon by way of said hook-type couplings. In this practical embodiment it is also preferred that said discharge end connecting means are the same or similar loop-type couplings to those disposed on said discharge end of said vehicle mounted agitator drum, such that a further discharge chute having suitable hook-type couplings disposed on a supply end thereof can be selectively suspended thereon.
Preferably said hook-type couplings of said discharge chute are reinforced by way of non-polymeric material inserts, preferably constructed of a metallic material, that are set into, and disposed internally of, said polymeric material relative to said hook-type couplings.
Preferably said skeletal frame structure includes a plurality of longitudinal stiffening bars, and at least one lateral stiffening rib. It is also preferred that skeletal frame structure includes at least five longitudinal stiffening bars and at least two lateral stiffening ribs. In a practical preferred embodiment, said skeletal frame structure includes at least one lateral stiffening rib disposed at, or near, each of said supply and discharge ends of said elongated body. In this practical preferred embodiment, it is preferred that said lateral stiffening ribs are disposed substantially in parallel to their respective supply or discharge end of said elongated body.
Preferably at least two of said at least five longitudinal stiffening bars are diagonally disposed relative to respective open sides of said convex outer surface. It is also preferred that all remaining longitudinal stiffening bars of said skeletal frame structure are disposed substantially in parallel to said open sides of said convex outer surface.
In a preferred embodiment, said skeletal frame structure includes a total of five longitudinal stiffening bars, wherein two are diagonally disposed relative to said open sides of said convex outer surface, and three are disposed in parallel to said open sides of said convex outer surface. In an alternative preferred embodiment, said skeletal frame structure includes a total of seven longitudinal stiffening bars, wherein four are diagonally disposed relative to said open sides of said convex outer surface, and three are disposed in parallel to said open sides of said convex outer surface.
In either preferred embodiment, it is preferred that of the three longitudinal stiffening bars disposed in parallel to said open sides of said convex outer surface, one is disposed generally at an apex of said convex outer surface of said elongated body, and the others are each disposed at, or near, a respective open side of said convex outer surface. It is also preferred that one end of each of said longitudinal stiffening bars that are diagonally disposed relative to said open sides of said convex outer surface are connected to said longitudinal stiffening bar disposed at said apex of said convex outer surface.
Preferably said polymeric material used to construct said discharge chute has a low frictional characteristic which results in a high operational efficiency in terms of said concrete mixture being dispensed via said concave inner guide surface of said discharge chute. It is also preferred that said polymeric material has superior wear resistant properties compared to that of the materials used to construct conventional metallic discharge chutes, resulting in an extended operational lifetime.
Preferably said polymeric material is polyurethane. In a practical preferred embodiment, said polyurethane is a rigid polyurethane having a set hardness of 74 Shore D, preferably Adiprene LF750D.
According to a further aspect of the present invention there is provided a method for manufacturing a discharge chute for guiding a concrete mixture from a discharge end of a vehicle mounted agitator drum to a predetermined pour area, said discharge chute including: an elongated body defining a substantially concave inner guide surface and a substantially convex outer surface which is generally concentric with said inner guide surface; a skeletal frame structure disposed on said convex outer surface of said elongated body for reinforcing said discharge chute against operational stresses; and, connecting means disposed at a supply end of said elongated body for attaching said discharge chute to said discharge end of said vehicle mounted agitator drum; wherein said elongated body, said skeletal frame structure and said connecting means are a single conjoint component constructed of a polymeric material; and wherein said method includes the steps of: heating said polymeric material to a predetermined moulding temperature; gravity feeding said heated polymeric material into a mould having integral skeletal frame structure channels and means for forming said connecting means; allowing said polymeric material to cool for a predetermined cooling time within said mould such that said discharge chute is formed; removing said discharge chute from said mould after said predetermined cooling time; and, curing said discharge chute in an oven for a predetermined curing time at a predetermined curing temperature. Preferably said predetermined cooling time is at least ten minutes, and said predetermined curing time is at least sixteen hours. It is also preferred that said predetermined curing temperature is 110 degrees Celsius.
In a practical preferred embodiment said mould is a three-part mould having a one-piece section for forming said substantially concave inner guide surface of said discharge chute, and two separate sections each for forming a part, preferably half, of said substantially convex outer surface of said discharge chute. It is preferred that said three-piece mould is constructed of fibreglass or aluminium. It is also preferred that at least one of said two separate convex forming sections of said three-piece mould include an opening for gravity feeding said heated polymeric material into said mould in accordance with said method described above.
In a practical preferred embodiment, said discharge chute further includes connecting means disposed at a discharge end of said elongated body for selectively, and removably, attaching said discharge chute to a further discharge chute or chutes. Preferably said mould further includes means for forming said discharge end connecting means.
In a further practical preferred embodiment, said discharge chute includes non-polymeric material inserts, preferably constructed of a metallic material, disposed relative to said supply end connecting means for reinforcing same.
Preferably said method further includes the step of positioning said inserts within said mould prior to said heated polymeric material being gravity fed therein, such that said metal inserts are set into, and disposed internally of, said polymeric material relative to said supply end connecting means after said predetermined cooling time.
Preferably said method further includes the step of cleaning and/or polishing any excess material off said discharge chute after said chute has been cured.
Preferably said polymeric material is polyurethane. In a practical preferred embodiment, said polyurethane is a rigid polyurethane, preferably Adiprene LF750D, having a set hardness of 74 Shore D. BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood and put into practical effect there shall now be described in detail preferred constructions of a discharge chute for a concrete truck, and a method of manufacturing same, in accordance with the invention. The ensuing description is given by way of non- limitative example only and is with reference to the accompanying drawings, wherein:
Fig. 1 is a discharge end perspective view of a discharge chute for a concrete truck made in accordance with a first preferred embodiment of the present invention;
Fig. 2a is a right side view of the discharge chute shown in Fig. 1 , the discharge chute shown partly in cross-section to illustrate the addition of preferred metal inserts which may be used to reinforce the hook-type couplings disposed at the supply end of the discharge chute;
Fig. 2b is a perspective view of one of the preferred metal reinforcing inserts shown in cross-section in Fig. 2a;
Fig. 3 is a supply end perspective view of the discharge chute shown in Fig. 1 , the discharge chute again shown partly in cross-section to illustrate the addition of the preferred metal reinforcing inserts shown in Fig. 2b;
Fig. 4 is a left side view of the discharge chute shown in Fig. 1 ;
Fig. 5 is a plan view of the discharge chute shown in Fig. 1 ;
Fig. 6 is an underneath view of the discharge chute shown in Fig. 1 ;
Fig. 7 is an underneath view of a discharge chute for a concrete truck made in accordance with a second preferred embodiment of the present invention;
Fig. 8 is a right side view of the discharge chute shown in Fig. 7, the discharge chute shown partly in cross-section to illustrate the addition of preferred metal inserts which may be used to reinforce the hook-type couplings disposed at the supply end of the discharge chute;
Fig. 9 is a supply end perspective view of a plurality of discharge chutes interconnected to one another, each of the discharge chutes being the same or similar to any one of the discharge chutes shown in Figs. 1 to 8; Fig. 10a is a cross-sectional end view of a preferred three-piece casting mould which may be used to construct any one of the discharge chute shown in Figs. 1 to 8 in accordance with a preferred method of manufacturing a discharge chute; Fig. 10b is a plan view of one part of the two-part convex producing section of the three-part mould shown in Fig. 10a; and,
Fig. 11 is a perspective view illustrating a procedural step of the preferred method of manufacturing a discharge chute in accordance with the present invention.
MODES FOR CARRYING OUT THE INVENTION
In Figs. 1 to 6, there is shown a perspective view of a discharge chute 10, made in accordance with a first preferred embodiment of the present invention. Although specifically described hereinafter as being suitable for guiding premixed concrete (not shown) from a discharge end of a vehicle mounted agitator drum (not shown) to a desired pour area, it should be understood that discharge chute 10 may be utilised to guide many other forms of materials being dispensed from many other forms of equipment, and as such the present invention is not limited to the specific example provided. Discharge chute 10 includes an elongated body 12 constructed entirely of a polymeric material and having a substantially concave inner guide surface 14 and a substantially convex outer surface 16 which is generally concentric with inner guide surface 14. Inner guide surface 14 provides a smooth surface for guiding premixed concrete (not shown) from a supply end s (see Figs. 1 , 3 & 5) of discharge chute 10 to a discharge end d thereof. In use, supply end s of discharge chute 10 is attached to a discharge end of a vehicle mounted agitator drum (not shown), or a discharge end of a main discharge chute or swivel chute (not shown) that is attached to the agitator drum, in order to provide a means of delivering premixed concrete to a desired location. Disposed on convex outer surface 16 of elongated body 12 is a skeletal frame structure 18 which is also constructed of a polymeric material, and which is provided to reinforce discharge chute 10 against operational stresses caused by the weight of the premixed concrete applied to discharge chute 10 during use.
As can be best seen in Fig. 6, skeletal frame structure 18 includes a plurality of longitudinal stiffening bars 20i ... 2On, and a plurality of lateral stiffening ribs 22i ... 22n, that together form a rigid framework that provides the necessary strength to discharge chute 10.
In accordance with the preferred discharge chute 10 shown in Figs. 1 to 6, skeletal frame structure 18 includes five longitudinal stiffening bars 201,202,203,204,2O5, and two lateral stiffening ribs 22^2. Referring to Fig. 6, it can be seen that all five longitudinal stiffening bars
20i ,202,203,204,205 extend from, or near, supply end s of discharge chute 10 and terminate at, or near, discharge end of thereof. Three 20i,2θ2,2θ3 θf the five longitudinal stiffening bars 20i,202,203,204,205 run end-to-end relative to supply and discharge ends s,d of discharge chute 10. Whilst the remaining two 204,2O5 longitudinal stiffening bars run diagonally across convex outer surface 16 of elongated body 12. These diagonal longitudinal stiffening bars 204,205 help to prevent flexing and/or twisting of discharge chute 10 during use and for this reason longitudinal stiffening bars 204,205 of skeletal frame structure 18 are important to the construction of discharge chute 10. One 2O2 of the three 20i,202,203 longitudinal stiffening bars that run end- to-end relative to supply and discharge ends s,d of discharge chute 10 is disposed generally at the apex of convex outer surface 16 of elongated body 12, whilst the remaining two 20i,2θ3 longitudinal stiffening bars are each disposed at, or near, a respective open side of convex outer surface 16. Of the two diagonally disposed longitudinal stiffening bars 204,20s, each run from, or near, discharge end d of discharge chute 10, relative to the apex of convex outer surface 16 and the longitudinal stiffening bar 2O2 disposed thereon, and terminate at, or near, supply end s of discharge chute 10, relative to a respective open side of convex outer surface 16 and the respective longitudinal stiffening bar 20i ,203 disposed thereon.
Of the two lateral stiffening ribs 22i,222 of skeletal frame structure 18, one rib 22i is disposed at, or near, supply end s of discharge chute 10, whilst the other rib 222 is disposed at, or near, the discharge end of thereof. Both stiffening ribs 22i,222 are generally disposed in parallel to their respective supply or discharge ends s,d of discharge chute 10.
It will be appreciated that the actual configuration and number of longitudinal stiffening bars 20i ... 2On, and lateral stiffening ribs 22i ... 22n, of skeletal frame structure 18 of discharge chute 10 can vary (see for example, the second preferred embodiment shown in Figs. 7 & 8) depending on the degree of operational stresses to which discharge chute 10 is to be exposed. A person skilled in the art would appreciate many such variations, and as such, the present invention should not be construed as limited to the specific example provided.
Disposed at supply end s of discharge chute 10 is a pair of hook-type couplings 24i,242 that are also constructed of a polymeric material, and that are each preferably formed integral with a respective longitudinal stiffening bar 20i,203. Supply end s hook-type couplings 24i,242 enable discharge chute 10 to be removably and pivotably mounted to cooperating loop-type couplings (not shown) disposed on the discharge end of a vehicle mounted agitator drum (not shown). The cooperating loop-type couplings disposed on the discharge end of an agitator drum enable discharge chute 10 to be suspended thereon by way of hook-type couplings 24i ,242. As is shown in Figs. 2a, 2b & 3, in order to provide added strength to discharge chute 10 relative to hook-type couplings 24i,242, each of longitudinal stiffening bars 20i,203 may be provided with a metal (hook-shaped) reinforcing insert 26i,262 that is disposed internally of the polymeric material used to construct hook-type couplings 24i,242. Although the use of metal inserts 26i,262 is proposed as a means of strengthening discharge chute 10 relative to hook-type couplings 24i,242, it should be appreciated that same may not be required should the polymeric material used to construct discharge chute 10 be sufficiently thick, relative to hook-type couplings 24i,242, to withstand operational stresses relative thereto. Similarly, although the use of metal inserts 26i,262 is proposed, it will be appreciated that other materials may be used to achieve a similar result. The present invention should therefore not be construed as limited to the specific example provided. At this point it will be appreciated that elongated body 12, skeletal frame structure 18 and hook-type couplings 24i,242 of discharge chute 10 are preferably a single conjoint component constructed of the same polymeric material utilising a suitable casting technique. A preferred method of manufacturing a discharge chute 10 in accordance with the present invention will be provided later in this description.
In terms of the polymeric material used to construct discharge chute 10, it is preferred that same has a low frictional characteristic which results in a high operational efficiency in terms of the premixed concrete being dispensed via concave inner guide surface 14 of discharge chute 10. It is also preferred that the selected polymeric material has superior wear resistant properties as compared to that of the materials used to construct conventional metallic discharge chutes (not shown), resulting in an extended operational lifetime.
It has been found that the polymeric material that is most suitable for constructing discharge chute 10 in accordance with the present invention is polyurethane. A preferred polyurethane is that distributed under the trade name
"Adiprene LF750D", which is commonly known as rigid polyurethane, and which has a set hardness of 74 Shore D.
Although a specific polymeric material has been proposed, namely polyurethane, it will be appreciated that many other materials could also be used to produce a discharge chute 10 in accordance with the present invention. The present invention should therefore not be construed as limited to the specific example provided.
Also shown in Figs. 1 to 6, is a pair of loop-type couplings 281,282 that are disposed at discharge end d of discharge chute 10, and which are each preferably formed integral with, or are affixed to, a respective longitudinal stiffening bar 20i,203 of skeletal frame structure 18.
Loop-type couplings 281,282 are preferably constructed of the same polymeric material to that used to construct the remaining conjoint polymeric material components 12,18,24 of discharge chute 10, but may alternatively be constructed of a different material, such as, for example metal. If constructed of the same polymeric material, it is preferred that elongated body 12, skeletal frame structure 18, hook-type couplings 24i,242, and loop-type couplings 28i,282 of discharge chute 10 are a single conjoint component constructed of the same polymeric material utilising a suitable casting technique. If constructed of a different material, loop-type couplings 281,282 may be set into longitudinal stiffening bars 20i,203 of skeletal frame structure 18 during the casting process, or may be mechanically fastened to same after the conjoint polymeric material components 12,18,24 of discharge chute 10 have been produced.
Discharge end d loop-type couplings 281,282, which may be the same as, or similar to, the cooperating loop-type couplings (not shown) disposed on the discharge end of a vehicle mounted agitator drum (not shown), enable discharge chute 10 to be selectively, and removably, attaching to a further discharge chute(s) 10 (see Fig. 9). Loop-type couplings 28i,282 also provide convenient handles to assist with moving and/or positioning discharge chutes 10 during use.
In Figs. 7 & 8, there is shown a discharge chute 100, made in accordance with a second preferred embodiment of the present invention. Like in the case of discharge chute 10 of Figs. 1 to 6, although specifically described hereinafter as being suitable for guiding premixed concrete (not shown) from a discharge end of a vehicle mounted agitator drum (not shown) to a desired pour area, it should be understood that discharge chute 100 may be utilised to guide many other forms of materials being dispensed from many other forms of equipment, and as such the present invention is not limited to the specific example provided. In Figs. 7 & 8, like reference numerals correspond to like parts shown in Figs. 1 to 6.
Discharge chute 100 of Figs. 7 & 8, varies to that of discharge chute 10 of Figs. 1 to 6, only in respect of the rigid framework design of skeletal frame structure 118. More particularly, when compared with discharge chute 10 of Figs. 1 to 6, it can be seen that skeletal frame structure 118, of discharge chute 100, includes an additional two diagonal longitudinal stiffening bars 12O6, 12O7, which provide added reinforcement to discharge chute 100 during use.
Referring particularly to the underneath view of Fig. 7, it can be seen that each of these additional diagonal longitudinal stiffening bars 1206,1207 run from, or near, supply end s of discharge chute 100, and terminate at, or near, the apex of convex outer surface 116 (and the longitudinal stiffening bar 12O2 disposed thereon), at a point which is intermediate of supply and discharge ends s,d of discharge chute 100.
This preferred dual diagonal stiffening bar design of skeletal frame structure 118 has been found to provide additional strength to discharge chute 100 in situations where excessive weight is applied to same. Hence, as compared to discharge chute 10 of Figs. 1 to 6, discharge chute 100 provides even greater resistance to flexing and/or twisting during use.
Although specific design examples of skeletal frame structures 18,118 have been provided, it will be appreciated that the actual configuration and number of diagonal longitudinal stiffening bars 204,1204 ... 2On, 12On of skeletal frame structure 18 of discharge chute 10 can vary depending on the degree of operational stresses to which discharge chute 10,100 is to be exposed. A person skilled in the art would appreciate many such variations, and as such, the present invention should not be construed as limited to the specific examples provided.
In Fig. 9 there is shown three discharge chutes 10 or 100 interconnected with one another by way of cooperating hook- and loop-type couplings 24i
Figure imgf000014_0001
or 124!,1242,1281,12S2, disposed on respective supply and discharge ends s,d of discharge chutes 10,100. This figure demonstrates that any suitable number of discharge chutes 1On, 10On made in accordance with the present invention can be interconnected with one another to increase the distance over which premixed concrete may be delivered.
To ensure that the flow of premixed concrete is not impeded when two or more discharge chutes 10,100 are interconnected with one another by way of hook- and loop-type couplings
Figure imgf000014_0002
or 124i,1242,128i,1282, discharge chutes 10,100 are so designed that the next chute 10,100 will fit under the first chute 10,100 in an overlap fashion. Referring particularly to the left- and right-hand side views of Figs. 2a,4 & 8, it can be seen that discharge end d of elongated body 12,112 is raised relative to its supply end s thereof. In this way, elongated body 12,112, at supply end s of a further discharge chute 10,100 (not shown in Figs. 2a,4 & 8), will fit sufficiently under discharge end d of the first discharge chute 10,100. Hence, the flow of premixed concrete (not shown) from the first discharge chute 10,100, to a further discharge chute 10,100, and so on, will not be interrupted.
A preferred method of manufacturing a discharge chute 10,100 made in accordance with the present invention will now be described with reference to Figs. 10a to 11. Although a specific method will now be described hereinafter as being suitable for manufacturing a discharge chute 10,100 made in accordance with the present invention, it should be understood that many other manufacturing methods could also be used to produce such a discharge chute 10,100, and as such the present invention is not limited to the specific method provided.
The preferred manufacturing method of the present invention utilises a mould 30 for casting a polymeric material discharge chute 10,100 having conjoint chute components 12,18,24,28 or 112,118,124,128, namely, elongated body 12,112, skeletal frame structure 18,118, hook-type couplings 24-ι,242 or 124i,1242, and loop-type couplings 28i,282 or 128L1282.
A suitable mould 30 for casting a polymeric material discharge chute 10,100 made in accordance with the present invention is shown in Fig. 10a. Mould 30 is a three-part casting mould having a one-piece section 32 for forming concave inner guide surface 14,114 of discharge chute 10,100, and two separate sections 34,36, each for forming a part, preferably half, of convex outer surface 16,116 of discharge chute 10,100.
Mould 30 may be constructed of any suitable material, but is preferably constructed of fibreglass or aluminium.
As can be seen in Fig. 10b, the two convex outer surface 16,116 forming sections 34,36 of mould 30 incorporate the required crevices or channels 220i ... 220n,222i ... 222n, necessary to produce longitudinal stiffening bars 20i,120i ... 2On, 12On, and lateral stiffening ribs 221 (122i ... 22n,122n of skeletal frame structure 18,118 (combined skeletal frame structure forming channels 218 as shown in Fig. 10a). In Fig. 10b, only one diagonal channel 220s is provided on convex outer surface 16,116 forming section 34, of mould 30, for producing a single diagonal longitudinal stiffening bar 220s. Hence, convex outer surface 16 forming section 34, of mould 30 of Fig. 10b, is specifically configured to be used to produce discharge chute 10 of Figs. 1 to 6.
It will be appreciated, although not shown in the drawings, that mould 30 of Figs. 10a & 10b may include any suitable number of channels 220i ... 220n,222i ... 222n, necessary to produce a skeletal frame structure 18,118 having any suitable number of longitudinal stiffening bars 20i,120i ... 2On, 12On, and lateral stiffening ribs 22i,122i ... 22n)122n, depending on the requirements of the chute being produced. For example, mould 30 may include dual diagonal channels 22On on each of convex outer surface 16,116 forming sections 34,36, in order to produce a discharge chute 100 made in accordance with the second preferred embodiment shown in Figs. 7 & 8. The present invention should therefore not be construed as limited to the specific example provided.
Although not shown in the drawings, mould 30 also includes the necessary means for forming hook- and loop-type couplings 24i,242,28i,282 or 124i,1242,128i,1282 of discharge chute 10,100. Similarly, although not shown, it should be appreciated that mould 30 may also include any necessary means for positioning reinforcing metal inserts 26i,262 or 126i,1262 within mould 30 prior to the polymeric construction material (not shown) being introduced therein.
Referring again to Fig. 10a, it can be seen that before mould 30 can be utilised for casting of a discharge chute 10,100, the three separate sections 32,34,36 of mould 30 must first be secured to one another by way of any suitable fastening means 38, for example, bolts and nuts 38 as shown. After assembly, the separate sections 32,34,36 of mould 30 only touch around their peripheral edges thereof which creates a gap 40 internally of mould 30 within which the polymeric construction material (not shown) is able to flow and subsequently set, which in turn results in the production of a solid conjoint discharge chute 10,100.
In order to enable the polymeric construction material (not shown) to be introduced into gap 40 provided within mould 30, at least one opening 42 (see, for example, Fig. 11) is provided in at least one of separate sections 32,34,36 of mould 30. Opening(s) 42 enables a polymeric material dispensing tool or funnel 44 to be inserted therein in order to gravity feed the required amount of polymeric material into mould 30 in accordance with the preferred method of manufacture of the present invention, which will now be described.
The preferred method of manufacturing a discharge chute 10,100 made in accordance with the present invention includes at least the following steps: heating a polymeric construction material to a suitable moulding temperature, the actual moulding temperature depending on the specific polymeric material used; gravity feeding the heated polymeric construction material into a mould 30 via opening(s) 42; allowing the heated polymeric construction material to cool for a predetermined cooling time within mould 30 such that discharge chute 10,100 is formed, the actual cooling time depending on the specific polymeric material used; removing discharge chute 10,100 from mould 30 after the predetermined cooling time; and, curing discharge chute 10,100 in an oven (not shown) for a predetermined curing time at a predetermined curing temperature, the actual curing time and curing temperature depending on the specific polymeric material used.
Any suitable polymeric construction material may be used, however it is preferred that the polymeric construction material is polyurethane. A preferred polyurethane is that distributed under the trade name "Adiprene LF750D", which is commonly known as rigid polyurethane, and which has a set hardness of 74 Shore D.
If "Adiprene LF750D" polyurethane is utilised as the construction material, the predetermined cooling time is at least ten minutes, and the predetermining curing time is at least sixteen hours at a predetermined curing temperature of 110 degrees Celsius. If it is desired to produce a discharge chute 10,100 having reinforcing metal inserts 261,262 or 126i,1262, cast internally of discharge chute 10,100 relative to supply end s hook-type couplings 24i,242 or 124i,1242 the preferred method of manufacture of the present invention further includes the step of: positioning the reinforcing metal inserts 261,262 or 126i,1262 within mould 30 prior to the heated polymeric material being gravity fed therein.
In some cases, a discharge chute 10,100 manufactured in accordance with the preferred method of the present invention may require some form of cleaning and/or polishing in order to ensure that at least the concave inner guide surface 14,114 of discharge chute 10,100 is smooth and ready for use. If such is desired, the preferred method of manufacture of the present invention may also include the step of: cleaning and/or polishing any excess construction material off discharge chute 10,100 after same has been cured. The present invention therefore provides a useful discharge chute 10,100 for a concrete truck, and a method for manufacturing same, that can be used as an alternative to a conventional metallic discharge chute, and which is relatively light and is substantially more durable when compared thereto.
Depending on the choice of polymeric or similar material used to construct the discharge chute of the present invention, it has been found that a resultant discharge chute can be up to 60% lighter than a conventional metallic chute of similar design. On top of this significant weight improvement, the discharge chute of the present invention also offers far superior operational resistance to wear and damage due to its non-metallic construction. Discharge chutes made in accordance with the present invention have been found to be extremely durable and long-wearing. Under test conditions, it was found that the severe impact caused by a vehicle reversing over a test discharge chute did not damage the chute due to the structural memory provided by the polymeric material used to construct same. This structural memory causes the chute to revert to its original shape once the impact pressure is released.
Finally, given the inherent properties of the polymeric or similar material used to construct a discharge chute in accordance with the present invention, build-up of concrete is less likely to occur, which makes it is easier to keep clean, and as a result thereof, substantially eliminates the possibility of deterioration of any of its components.
While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). The present invention is intended to cover any variations, uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth. Finally, as the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and the appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced.

Claims

CLAIWIS:
1. A discharge chute for guiding a concrete mixture from a discharge end of a vehicle mounted agitator drum to a predetermined pour area, said discharge chute including: an elongated body defining a substantially concave inner guide surface and a substantially convex outer surface which is generally concentric with said inner guide surface; a skeletal frame structure disposed on said convex outer surface of said elongated body for reinforcing said discharge chute against operational stresses; and, connecting means disposed at a supply end of said elongated body for attaching said discharge chute to said discharge end of said vehicle mounted agitator drum; wherein said elongated body, said skeletal frame structure and said connecting means are a single conjoint component constructed of a polymeric material.
2. The discharge chute as claimed in claim 1 , further including connecting means disposed at a discharge end of said elongated body for selectively, and removably, attaching said discharge chute to a further discharge chute or chutes.
3. The discharge chute as claimed in claim 2, wherein said elongated body, said skeletal frame structure, said supply end connecting means and said discharge end connecting means are a single conjoint component constructed of the same polymeric material.
4. The discharge chute as claimed in claim 2, wherein said discharge end connecting means are separate components that are mechanically fastened to said discharge chute.
5. The discharge chute as claimed in any one of claims 2 to 4, wherein said supply end connecting means are hook-type couplings that enable said discharge chute to be removably and pivotably mounted to cooperating couplings disposed on said discharge end of said vehicle mounted agitator drum.
6. The discharge chute as claimed in claim 5, wherein said cooperating couplings disposed on said discharge end of said vehicle mounted agitator drum are loop-type couplings that enable said discharge chute to be suspended thereon by way of said hook-type couplings disposed on said supply end of said discharge chute.
7. The discharge chute as claimed in claim 6, wherein said discharge end connecting means are the same or similar loop-type couplings to those disposed on said discharge end of said vehicle mounted agitator drum, whereby a further discharge chute having said hook-type couplings disposed on a supply end thereof can be selectively suspended thereon.
8. The discharge chute as claimed in claim 5, wherein said hook-type couplings disposed at said supply end of said discharge chute are reinforced by way of non-polymeric material inserts that are set into, and disposed internally of, said polymeric material relative to said hook-type couplings.
9. The discharge chute as claimed in claim 8, wherein said inserts are constructed of a metallic material.
10. The discharge chute as claimed in any one of the preceding claims, wherein said skeletal frame structure includes a plurality of longitudinal stiffening bars, and at least one lateral stiffening rib.
11. The discharge chute as claimed in claim 10, wherein said skeletal frame structure includes at least five longitudinal stiffening bars and at least two lateral stiffening ribs.
12. The discharge chute as claimed in claim 11, including at least one lateral stiffening rib disposed at, or near, each of said supply and discharge ends of said elongated body.
13. The discharge chute as claimed in claim 12, wherein said lateral stiffening ribs are disposed substantially in parallel to their respective supply or discharge end of said elongated body.
14. The discharge chute as claimed in any one of claims 11 to 13, wherein at least two of said at least five longitudinal stiffening bars are diagonally disposed relative to respective open sides of said convex outer surface.
15. The discharge chute as claimed in claim 14, wherein all remaining longitudinal stiffening bars of said skeletal frame structure are disposed substantially in parallel to said open sides of said convex outer surface.
16. The discharge chute as claimed in claim 15, including a total of five longitudinal stiffening bars, wherein two are diagonally disposed relative to said open sides of said convex outer surface, and three are disposed in parallel to said open sides of said convex outer surface.
17. The discharge chute as claimed in claim 15, including a total of seven longitudinal stiffening bars, wherein four are diagonally disposed relative to said open sides of said convex outer surface, and three are disposed in parallel to said open sides of said convex outer surface.
18. The discharge chute as claimed in claim 16 or claim 17, wherein of the three longitudinal stiffening bars disposed in parallel to said open sides of said convex outer surface, one is disposed generally at an apex of said convex outer surface of said elongated body, and the others are each disposed at, or near, a respective open side of said convex outer surface.
19. The discharge chute as claimed in claim 18, wherein one end of each of said longitudinal stiffening bars that are diagonally disposed relative to said open sides of said convex outer surface are connected to said longitudinal stiffening bar disposed at said apex of said convex outer surface.
20. The discharge chute as claimed in any one of the preceding claims, wherein said polymeric material has a low frictional characteristic which results in a high operational efficiency in terms of said concrete mixture being dispensed via said concave inner guide surface of said discharge chute.
21. The discharge chute as claimed in any one of the preceding claims, wherein said polymeric material is polyurethane.
22. The discharge chute as claimed in claim 21 , wherein said polyurethane is a rigid polyurethane having a set hardness of 74 Shore D.
23. The discharge chute as claimed in claim 22, wherein said rigid polyurethane is Adiprene LF750D.
24. A method for manufacturing a discharge chute for guiding a concrete mixture from a discharge end of a vehicle mounted agitator drum to a predetermined pour area, said discharge chute including: an elongated body defining a substantially concave inner guide surface and a substantially convex outer surface which is generally concentric with said inner guide surface; a skeletal frame structure disposed on said convex outer surface of said elongated body for reinforcing said discharge chute against operational stresses; and, connecting means disposed at a supply end of said elongated body for attaching said discharge chute to said discharge end of said vehicle mounted agitator drum; wherein said elongated body, said skeletal frame structure and said connecting means are a single conjoint component constructed of a polymeric material; and wherein said method includes the steps of: heating said polymeric material to a predetermined moulding temperature; gravity feeding said heated polymeric material into a mould having integral skeletal frame structure channels and means for forming said connecting means; allowing said polymeric material to cool for a predetermined cooling time within said mould such that said discharge chute is formed; removing said discharge chute from said mould after said predetermined cooling time; and, curing said discharge chute in an oven for a predetermined curing time at a predetermined curing temperature.
25. The method as claimed in claim 24, wherein said predetermined cooling time is at least ten minutes.
26. The method as claimed in claim 24 or claim 25, wherein said predetermined curing time is at least sixteen hours.
27. The method as claimed in claim 26, wherein said predetermined curing temperature is 110 degrees Celsius.
28. The method as claimed in any one of claims 24 to 27, wherein said mould is a three-part mould.
29. The method as claimed in claim 28, wherein said three-part mould includes a one-piece section for forming said substantially concave inner guide surface of said discharge chute, and two separate sections each for forming a part of said substantially convex outer surface of said discharge chute.
30. The method as claimed in claim 29, wherein each of said two separate sections of said three-part mould produce half of said substantially convex outer surface of said discharge chute.
31. The method as claimed in any one of claims 28 to 30, wherein said three-piece mould is constructed of fibreglass or aluminium.
32. The method as claimed in any one of claims 29 to 31 , wherein at least one of said two separate convex forming sections of said three-piece mould include an opening for gravity feeding said heated polymeric material into said mould.
33. The method as claimed in any one of claims 24 to 32, wherein said discharge chute further includes connecting means disposed at a discharge end of said elongated body for selectively, and removably, attaching said discharge chute to a further discharge chute or chutes.
34. The method as claimed in claim 33, wherein said mould further includes means for forming said discharge end connecting means.
35. The method as claimed any one of claims 24 to 34, wherein said discharge chute further includes non-polymeric material inserts disposed relative to said supply end connecting means for reinforcing same.
36. The method as claimed in claim 35, wherein said inserts are constructed of a metallic material.
37. The method as claimed in claim 35 or claim 36, further including the step of: positioning said inserts within said mould prior to said heated polymeric material being gravity fed therein, such that said inserts are set into, and disposed internally of, said polymeric material relative to said supply end connecting means after said predetermined cooling time.
38. The method as claimed in any one of claims 24 to 37, further including the step of: cleaning and/or polishing any excess material off said discharge chute after said chute has been cured.
39. The method as claimed in any one of claims 24 to 38, wherein said polymeric material is polyurethane.
40. The method as claimed in claim 39, wherein said polyurethane is a rigid polyurethane, having a set hardness of 74 Shore D.
41. The method as claimed in claim 40, wherein said rigid polyurethane is Adiprene LF750D.
PCT/AU2007/001773 2007-07-12 2007-11-16 Discharge chute for a concrete truck and method of manufacturing same WO2009006667A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU2007903793 2007-07-12
AU2007903793A AU2007903793A0 (en) 2007-07-12 Discharge Chute for a Concrete Truck and Method of Manufacturing Same

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WO2009006667A1 true WO2009006667A1 (en) 2009-01-15

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5184706A (en) * 1990-01-26 1993-02-09 Mcneilus Truck & Manufacturing, Inc. Polymeric composite discharge chutes for concrete having a wear resistant liner
US6367606B1 (en) * 1999-10-15 2002-04-09 Soq, Llc Concrete chute with liner
US6938749B1 (en) * 2000-11-15 2005-09-06 Oshkosh Truck Corporation Discharge chute for concrete

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5184706A (en) * 1990-01-26 1993-02-09 Mcneilus Truck & Manufacturing, Inc. Polymeric composite discharge chutes for concrete having a wear resistant liner
US6367606B1 (en) * 1999-10-15 2002-04-09 Soq, Llc Concrete chute with liner
US6938749B1 (en) * 2000-11-15 2005-09-06 Oshkosh Truck Corporation Discharge chute for concrete

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